UTF16 (ICU4J 76)

java.lang.Object
- com.ibm.icu.text.UTF16

```
public final class UTF16
extends Object
```
Standalone utility class providing UTF16 character conversions and indexing conversions.

Code that uses strings alone rarely need modification. By design, UTF-16 does not allow overlap, so searching for strings is a safe operation. Similarly, concatenation is always safe. Substringing is safe if the start and end are both on UTF-32 boundaries. In normal code, the values for start and end are on those boundaries, since they arose from operations like searching. If not, the nearest UTF-32 boundaries can be determined using bounds().
Examples:
The following examples illustrate use of some of these methods.
```
 // iteration forwards: Original
 for (int i = 0; i < s.length(); ++i) {
     char ch = s.charAt(i);
     doSomethingWith(ch);
 }

 // iteration forwards: Changes for UTF-32
 int ch;
 for (int i = 0; i < s.length(); i += UTF16.getCharCount(ch)) {
     ch = UTF16.charAt(s, i);
     doSomethingWith(ch);
 }

 // iteration backwards: Original
 for (int i = s.length() - 1; i >= 0; --i) {
     char ch = s.charAt(i);
     doSomethingWith(ch);
 }

 // iteration backwards: Changes for UTF-32
 int ch;
 for (int i = s.length() - 1; i > 0; i -= UTF16.getCharCount(ch)) {
     ch = UTF16.charAt(s, i);
     doSomethingWith(ch);
 }
 
```
Notes:
- Naming: For clarity, High and Low surrogates are called Lead and Trail in the API, which gives a better sense of their ordering in a string. offset16 and offset32 are used to distinguish offsets to UTF-16 boundaries vs offsets to UTF-32 boundaries. int char32 is used to contain UTF-32 characters, as opposed to char16, which is a UTF-16 code unit.
- Roundtripping Offsets: You can always roundtrip from a UTF-32 offset to a UTF-16 offset and back. Because of the difference in structure, you can roundtrip from a UTF-16 offset to a UTF-32 offset and back if and only if bounds(string, offset16) != TRAIL.
- Exceptions: The error checking will throw an exception if indices are out of bounds. Other than than that, all methods will behave reasonably, even if unmatched surrogates or out-of-bounds UTF-32 values are present. UCharacter.isLegal() can be used to check for validity if desired.
- Unmatched Surrogates: If the string contains unmatched surrogates, then these are counted as one UTF-32 value. This matches their iteration behavior, which is vital. It also matches common display practice as missing glyphs (see the Unicode Standard Section 5.4, 5.5).
- Optimization: The method implementations may need optimization if the compiler doesn't fold static final methods. Since surrogate pairs will form an exceeding small percentage of all the text in the world, the singleton case should always be optimized for.
Author:

Mark Davis, with help from Markus Scherer

Status:
Stable ICU 2.1.

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static class UTF16.StringComparator
UTF16 string comparator class.

Nested Classes
Modifier and Type	Class and Description
`static class`	`UTF16.StringComparator` UTF16 string comparator class.

Field Summary

Fields
Modifier and Type	Field and Description
`static int`	`CODEPOINT_MAX_VALUE` The highest Unicode code point value (scalar value) according to the Unicode Standard.
`static int`	`CODEPOINT_MIN_VALUE` The lowest Unicode code point value.
`static int`	`LEAD_SURROGATE_BOUNDARY` Value returned in `bounds()`.
`static int`	`LEAD_SURROGATE_MAX_VALUE` Lead surrogate maximum value
`static int`	`LEAD_SURROGATE_MIN_VALUE` Lead surrogate minimum value
`static int`	`SINGLE_CHAR_BOUNDARY` Value returned in `bounds()`.
`static int`	`SUPPLEMENTARY_MIN_VALUE` The minimum value for Supplementary code points
`static int`	`SURROGATE_MAX_VALUE` Maximum surrogate value
`static int`	`SURROGATE_MIN_VALUE` Surrogate minimum value
`static int`	`TRAIL_SURROGATE_BOUNDARY` Value returned in `bounds()`.
`static int`	`TRAIL_SURROGATE_MAX_VALUE` Trail surrogate maximum value
`static int`	`TRAIL_SURROGATE_MIN_VALUE` Trail surrogate minimum value

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static int`	`append(char[] target, int limit, int char32)` Adds a codepoint to offset16 position of the argument char array.
`static StringBuffer`	`append(StringBuffer target, int char32)` Append a single UTF-32 value to the end of a StringBuffer.
`static StringBuffer`	`appendCodePoint(StringBuffer target, int cp)` Cover JDK 1.5 APIs.
`static int`	`bounds(char[] source, int start, int limit, int offset16)` Returns the type of the boundaries around the char at offset16.
`static int`	`bounds(StringBuffer source, int offset16)` Returns the type of the boundaries around the char at offset16.
`static int`	`bounds(String source, int offset16)` Returns the type of the boundaries around the char at offset16.
`static int`	`charAt(char[] source, int start, int limit, int offset16)` Extract a single UTF-32 value from a substring.
`static int`	`charAt(CharSequence source, int offset16)` Extract a single UTF-32 value from a string.
`static int`	`charAt(Replaceable source, int offset16)` Extract a single UTF-32 value from a string.
`static int`	`charAt(StringBuffer source, int offset16)` Extract a single UTF-32 value from a string.
`static int`	`charAt(String source, int offset16)` Extract a single UTF-32 value from a string.
`static int`	`compareCodePoint(int codePoint, CharSequence s)` Utility for comparing a code point to a string without having to create a new string.
`static int`	`countCodePoint(char[] source, int start, int limit)` Number of codepoints in a UTF16 char array substring
`static int`	`countCodePoint(String source)` Number of codepoints in a UTF16 String
`static int`	`countCodePoint(StringBuffer source)` Number of codepoints in a UTF16 String buffer
`static int`	`delete(char[] target, int limit, int offset16)` Removes the codepoint at the specified position in this target (shortening target by 1 character if the codepoint is a non-supplementary, 2 otherwise).
`static StringBuffer`	`delete(StringBuffer target, int offset16)` Removes the codepoint at the specified position in this target (shortening target by 1 character if the codepoint is a non-supplementary, 2 otherwise).
`static int`	`findCodePointOffset(char[] source, int start, int limit, int offset16)` Returns the UTF-32 offset corresponding to the first UTF-32 boundary at the given UTF-16 offset.
`static int`	`findCodePointOffset(StringBuffer source, int offset16)` Returns the UTF-32 offset corresponding to the first UTF-32 boundary at the given UTF-16 offset.
`static int`	`findCodePointOffset(String source, int offset16)` Returns the UTF-32 offset corresponding to the first UTF-32 boundary at or after the given UTF-16 offset.
`static int`	`findOffsetFromCodePoint(char[] source, int start, int limit, int offset32)` Returns the UTF-16 offset that corresponds to a UTF-32 offset.
`static int`	`findOffsetFromCodePoint(StringBuffer source, int offset32)` Returns the UTF-16 offset that corresponds to a UTF-32 offset.
`static int`	`findOffsetFromCodePoint(String source, int offset32)` Returns the UTF-16 offset that corresponds to a UTF-32 offset.
`static int`	`getCharCount(int char32)` Determines how many chars this char32 requires.
`static char`	`getLeadSurrogate(int char32)` Returns the lead surrogate.
`static int`	`getSingleCodePoint(CharSequence s)` Utility for getting a code point from a CharSequence that contains exactly one code point.
`static char`	`getTrailSurrogate(int char32)` Returns the trail surrogate.
`static boolean`	`hasMoreCodePointsThan(char[] source, int start, int limit, int number)` Check if the sub-range of char array, from argument start to limit, contains more Unicode code points than a certain number.
`static boolean`	`hasMoreCodePointsThan(StringBuffer source, int number)` Check if the string buffer contains more Unicode code points than a certain number.
`static boolean`	`hasMoreCodePointsThan(String source, int number)` Check if the string contains more Unicode code points than a certain number.
`static int`	`indexOf(String source, int char32)` Returns the index within the argument UTF16 format Unicode string of the first occurrence of the argument codepoint.
`static int`	`indexOf(String source, int char32, int fromIndex)` Returns the index within the argument UTF16 format Unicode string of the first occurrence of the argument codepoint.
`static int`	`indexOf(String source, String str)` Returns the index within the argument UTF16 format Unicode string of the first occurrence of the argument string str.
`static int`	`indexOf(String source, String str, int fromIndex)` Returns the index within the argument UTF16 format Unicode string of the first occurrence of the argument string str.
`static int`	`insert(char[] target, int limit, int offset16, int char32)` Inserts char32 codepoint into target at the argument offset16.
`static StringBuffer`	`insert(StringBuffer target, int offset16, int char32)` Inserts char32 codepoint into target at the argument offset16.
`static boolean`	`isLeadSurrogate(int codePoint)` Determines whether the code point is a lead surrogate.
`static boolean`	`isSurrogate(int codePoint)` Determines whether the code point is a surrogate.
`static boolean`	`isTrailSurrogate(int codePoint)` Determines whether the code point is a trail surrogate.
`static int`	`lastIndexOf(String source, int char32)` Returns the index within the argument UTF16 format Unicode string of the last occurrence of the argument codepoint.
`static int`	`lastIndexOf(String source, int char32, int fromIndex)` Returns the index within the argument UTF16 format Unicode string of the last occurrence of the argument codepoint, where the result is less than or equals to fromIndex.
`static int`	`lastIndexOf(String source, String str)` Returns the index within the argument UTF16 format Unicode string of the last occurrence of the argument string str.
`static int`	`lastIndexOf(String source, String str, int fromIndex)` Returns the index within the argument UTF16 format Unicode string of the last occurrence of the argument string str, where the result is less than or equals to fromIndex.
`static int`	`moveCodePointOffset(char[] source, int start, int limit, int offset16, int shift32)` Shifts offset16 by the argument number of codepoints within a subarray.
`static int`	`moveCodePointOffset(StringBuffer source, int offset16, int shift32)` Shifts offset16 by the argument number of codepoints
`static int`	`moveCodePointOffset(String source, int offset16, int shift32)` Shifts offset16 by the argument number of codepoints
`static String`	`newString(int[] codePoints, int offset, int count)` Cover JDK 1.5 API.
`static String`	`replace(String source, int oldChar32, int newChar32)` Returns a new UTF16 format Unicode string resulting from replacing all occurrences of oldChar32 in source with newChar32.
`static String`	`replace(String source, String oldStr, String newStr)` Returns a new UTF16 format Unicode string resulting from replacing all occurrences of oldStr in source with newStr.
`static StringBuffer`	`reverse(StringBuffer source)` Reverses a UTF16 format Unicode string and replaces source's content with it.
`static int`	`setCharAt(char[] target, int limit, int offset16, int char32)` Set a code point into a UTF16 position in a char array.
`static void`	`setCharAt(StringBuffer target, int offset16, int char32)` Set a code point into a UTF16 position.
`static String`	`valueOf(char[] source, int start, int limit, int offset16)` Convenience method.
`static String`	`valueOf(int char32)` Convenience method corresponding to String.valueOf(char).
`static String`	`valueOf(StringBuffer source, int offset16)` Convenience method corresponding to StringBuffer.valueOf(codepoint at offset16).
`static String`	`valueOf(String source, int offset16)` Convenience method corresponding to String.valueOf(codepoint at offset16).

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - SINGLE_CHAR_BOUNDARY
```
public static final int SINGLE_CHAR_BOUNDARY
```
    Value returned in bounds(). These values are chosen specifically so that it actually represents the position of the character [offset16 - (value >> 2), offset16 + (value & 3)]
    
    See Also:
    
    Constant Field Values
    
    Status:
    Stable ICU 2.1.
  - LEAD_SURROGATE_BOUNDARY
```
public static final int LEAD_SURROGATE_BOUNDARY
```
    Value returned in bounds(). These values are chosen specifically so that it actually represents the position of the character [offset16 - (value >> 2), offset16 + (value & 3)]
    
    See Also:
    
    Constant Field Values
    
    Status:
    Stable ICU 2.1.
  - TRAIL_SURROGATE_BOUNDARY
```
public static final int TRAIL_SURROGATE_BOUNDARY
```
    Value returned in bounds(). These values are chosen specifically so that it actually represents the position of the character [offset16 - (value >> 2), offset16 + (value & 3)]
    
    See Also:
    
    Constant Field Values
    
    Status:
    Stable ICU 2.1.
  - CODEPOINT_MIN_VALUE
```
public static final int CODEPOINT_MIN_VALUE
```
    The lowest Unicode code point value.
    
    See Also:
    
    Constant Field Values
    
    Status:
    Stable ICU 2.1.
  - CODEPOINT_MAX_VALUE
```
public static final int CODEPOINT_MAX_VALUE
```
    The highest Unicode code point value (scalar value) according to the Unicode Standard.
    
    See Also:
    
    Constant Field Values
    
    Status:
    Stable ICU 2.1.
  - SUPPLEMENTARY_MIN_VALUE
```
public static final int SUPPLEMENTARY_MIN_VALUE
```
    The minimum value for Supplementary code points
    
    See Also:
    
    Constant Field Values
    
    Status:
    Stable ICU 2.1.
  - LEAD_SURROGATE_MIN_VALUE
```
public static final int LEAD_SURROGATE_MIN_VALUE
```
    Lead surrogate minimum value
    
    See Also:
    
    Constant Field Values
    
    Status:
    Stable ICU 2.1.
  - TRAIL_SURROGATE_MIN_VALUE
```
public static final int TRAIL_SURROGATE_MIN_VALUE
```
    Trail surrogate minimum value
    
    See Also:
    
    Constant Field Values
    
    Status:
    Stable ICU 2.1.
  - LEAD_SURROGATE_MAX_VALUE
```
public static final int LEAD_SURROGATE_MAX_VALUE
```
    Lead surrogate maximum value
    
    See Also:
    
    Constant Field Values
    
    Status:
    Stable ICU 2.1.
  - TRAIL_SURROGATE_MAX_VALUE
```
public static final int TRAIL_SURROGATE_MAX_VALUE
```
    Trail surrogate maximum value
    
    See Also:
    
    Constant Field Values
    
    Status:
    Stable ICU 2.1.
  - SURROGATE_MIN_VALUE
```
public static final int SURROGATE_MIN_VALUE
```
    Surrogate minimum value
    
    See Also:
    
    Constant Field Values
    
    Status:
    Stable ICU 2.1.
  - SURROGATE_MAX_VALUE
```
public static final int SURROGATE_MAX_VALUE
```
    Maximum surrogate value
    
    See Also:
    
    Constant Field Values
    
    Status:
    Stable ICU 2.1.
- Method Detail
  - charAt
```
public static int charAt(String source,
                         int offset16)
```
    Extract a single UTF-32 value from a string. Used when iterating forwards or backwards (with UTF16.getCharCount(), as well as random access. If a validity check is required, use UCharacter.isLegal() on the return value. If the char retrieved is part of a surrogate pair, its supplementary character will be returned. If a complete supplementary character is not found the incomplete character will be returned
    
    Parameters:
    
    source - Array of UTF-16 chars
    
    offset16 - UTF-16 offset to the start of the character.
    
    Returns:
    
    UTF-32 value for the UTF-32 value that contains the char at offset16. The boundaries of that codepoint are the same as in bounds32().
    
    Throws:
    
    IndexOutOfBoundsException - Thrown if offset16 is out of bounds.
    
    Status:
    Stable ICU 2.1.
  - charAt
```
public static int charAt(CharSequence source,
                         int offset16)
```
    Extract a single UTF-32 value from a string. Used when iterating forwards or backwards (with UTF16.getCharCount(), as well as random access. If a validity check is required, use UCharacter.isLegal() on the return value. If the char retrieved is part of a surrogate pair, its supplementary character will be returned. If a complete supplementary character is not found the incomplete character will be returned
    
    Parameters:
    
    source - Array of UTF-16 chars
    
    offset16 - UTF-16 offset to the start of the character.
    
    Returns:
    
    UTF-32 value for the UTF-32 value that contains the char at offset16. The boundaries of that codepoint are the same as in bounds32().
    
    Throws:
    
    IndexOutOfBoundsException - Thrown if offset16 is out of bounds.
    
    Status:
    Stable ICU 2.1.
  - charAt
```
public static int charAt(StringBuffer source,
                         int offset16)
```
    Extract a single UTF-32 value from a string. Used when iterating forwards or backwards (with UTF16.getCharCount(), as well as random access. If a validity check is required, use UCharacter.isLegal() on the return value. If the char retrieved is part of a surrogate pair, its supplementary character will be returned. If a complete supplementary character is not found the incomplete character will be returned
    
    Parameters:
    
    source - UTF-16 chars string buffer
    
    offset16 - UTF-16 offset to the start of the character.
    
    Returns:
    
    UTF-32 value for the UTF-32 value that contains the char at offset16. The boundaries of that codepoint are the same as in bounds32().
    
    Throws:
    
    IndexOutOfBoundsException - Thrown if offset16 is out of bounds.
    
    Status:
    Stable ICU 2.1.
  - charAt
```
public static int charAt(char[] source,
                         int start,
                         int limit,
                         int offset16)
```
    Extract a single UTF-32 value from a substring. Used when iterating forwards or backwards (with UTF16.getCharCount(), as well as random access. If a validity check is required, use UCharacter.isLegal() on the return value. If the char retrieved is part of a surrogate pair, its supplementary character will be returned. If a complete supplementary character is not found the incomplete character will be returned
    
    Parameters:
    
    source - Array of UTF-16 chars
    
    start - Offset to substring in the source array for analyzing
    
    limit - Offset to substring in the source array for analyzing
    
    offset16 - UTF-16 offset relative to start
    
    Returns:
    
    UTF-32 value for the UTF-32 value that contains the char at offset16. The boundaries of that codepoint are the same as in bounds32().
    
    Throws:
    
    IndexOutOfBoundsException - Thrown if offset16 is not within the range of start and limit.
    
    Status:
    Stable ICU 2.1.
  - charAt
```
public static int charAt(Replaceable source,
                         int offset16)
```
    Extract a single UTF-32 value from a string. Used when iterating forwards or backwards (with UTF16.getCharCount(), as well as random access. If a validity check is required, use UCharacter.isLegal() on the return value. If the char retrieved is part of a surrogate pair, its supplementary character will be returned. If a complete supplementary character is not found the incomplete character will be returned
    
    Parameters:
    
    source - UTF-16 chars string buffer
    
    offset16 - UTF-16 offset to the start of the character.
    
    Returns:
    
    UTF-32 value for the UTF-32 value that contains the char at offset16. The boundaries of that codepoint are the same as in bounds32().
    
    Throws:
    
    IndexOutOfBoundsException - Thrown if offset16 is out of bounds.
    
    Status:
    Stable ICU 2.1.
  - getCharCount
```
public static int getCharCount(int char32)
```
    Determines how many chars this char32 requires. If a validity check is required, use isLegal() on char32 before calling.
    
    Parameters:
    
    char32 - The input codepoint.
    
    Returns:
    
    2 if is in supplementary space, otherwise 1.
    
    Status:
    Stable ICU 2.1.
  - bounds
```
public static int bounds(String source,
                         int offset16)
```
    Returns the type of the boundaries around the char at offset16. Used for random access.
    Parameters:
    
    source - Text to analyse
    
    offset16 - UTF-16 offset
    
    Returns:
    SINGLE_CHAR_BOUNDARY : a single char; the bounds are [offset16, offset16+1]
    LEAD_SURROGATE_BOUNDARY : a surrogate pair starting at offset16; the bounds are [offset16, offset16 + 2]
    TRAIL_SURROGATE_BOUNDARY : a surrogate pair starting at offset16 - 1; the bounds are [offset16 - 1, offset16 + 1]
    For bit-twiddlers, the return values for these are chosen so that the boundaries can be gotten by: [offset16 - (value >> 2), offset16 + (value & 3)].
    Throws:
    
    IndexOutOfBoundsException - If offset16 is out of bounds.
    
    Status:
    Stable ICU 2.1.
  - bounds
```
public static int bounds(StringBuffer source,
                         int offset16)
```
    Returns the type of the boundaries around the char at offset16. Used for random access.
    Parameters:
    
    source - String buffer to analyse
    
    offset16 - UTF16 offset
    
    Returns:
    SINGLE_CHAR_BOUNDARY : a single char; the bounds are [offset16, offset16 + 1]
    LEAD_SURROGATE_BOUNDARY : a surrogate pair starting at offset16; the bounds are [offset16, offset16 + 2]
    TRAIL_SURROGATE_BOUNDARY : a surrogate pair starting at offset16 - 1; the bounds are [offset16 - 1, offset16 + 1]
    For bit-twiddlers, the return values for these are chosen so that the boundaries can be gotten by: [offset16 - (value >> 2), offset16 + (value & 3)].
    Throws:
    
    IndexOutOfBoundsException - If offset16 is out of bounds.
    
    Status:
    Stable ICU 2.1.
  - bounds
```
public static int bounds(char[] source,
                         int start,
                         int limit,
                         int offset16)
```
    Returns the type of the boundaries around the char at offset16. Used for random access. Note that the boundaries are determined with respect to the subarray, hence the char array {0xD800, 0xDC00} has the result SINGLE_CHAR_BOUNDARY for start = offset16 = 0 and limit = 1.
    Parameters:
    
    source - Char array to analyse
    
    start - Offset to substring in the source array for analyzing
    
    limit - Offset to substring in the source array for analyzing
    
    offset16 - UTF16 offset relative to start
    
    Returns:
    SINGLE_CHAR_BOUNDARY : a single char; the bounds are
    LEAD_SURROGATE_BOUNDARY : a surrogate pair starting at offset16; the bounds are [offset16, offset16 + 2]
    TRAIL_SURROGATE_BOUNDARY : a surrogate pair starting at offset16 - 1; the bounds are [offset16 - 1, offset16 + 1]
    For bit-twiddlers, the boundary values for these are chosen so that the boundaries can be gotten by: [offset16 - (boundvalue >> 2), offset16 + (boundvalue & 3)].
    Throws:
    
    IndexOutOfBoundsException - If offset16 is not within the range of start and limit.
    
    Status:
    Stable ICU 2.1.
  - isSurrogate
```
public static boolean isSurrogate(int codePoint)
```
    Determines whether the code point is a surrogate.
    
    Parameters:
    
    codePoint - The input character. (In ICU 2.1-69 the type of this parameter was char.)
    
    Returns:
    
    true If the input code point is a surrogate.
    
    Status:
    Stable ICU 70.
  - isTrailSurrogate
```
public static boolean isTrailSurrogate(int codePoint)
```
    Determines whether the code point is a trail surrogate.
    
    Parameters:
    
    codePoint - The input character. (In ICU 2.1-69 the type of this parameter was char.)
    
    Returns:
    
    true If the input code point is a trail surrogate.
    
    Status:
    Stable ICU 70.
  - isLeadSurrogate
```
public static boolean isLeadSurrogate(int codePoint)
```
    Determines whether the code point is a lead surrogate.
    
    Parameters:
    
    codePoint - The input character. (In ICU 2.1-69 the type of this parameter was char.)
    
    Returns:
    
    true If the input code point is a lead surrogate
    
    Status:
    Stable ICU 70.
  - getLeadSurrogate
```
public static char getLeadSurrogate(int char32)
```
    Returns the lead surrogate. If a validity check is required, use isLegal() on char32 before calling.
    
    Parameters:
    
    char32 - The input character.
    
    Returns:
    
    lead surrogate if the getCharCount(ch) is 2;
    and 0 otherwise (note: 0 is not a valid lead surrogate).
    
    Status:
    Stable ICU 2.1.
  - getTrailSurrogate
```
public static char getTrailSurrogate(int char32)
```
    Returns the trail surrogate. If a validity check is required, use isLegal() on char32 before calling.
    
    Parameters:
    
    char32 - The input character.
    
    Returns:
    
    the trail surrogate if the getCharCount(ch) is 2;
    otherwise the character itself
    
    Status:
    Stable ICU 2.1.
  - valueOf
```
public static String valueOf(int char32)
```
    Convenience method corresponding to String.valueOf(char). Returns a one or two char string containing the UTF-32 value in UTF16 format. If a validity check is required, use UCharacter.isLegal(int) on char32 before calling.
    
    Parameters:
    
    char32 - The input character.
    
    Returns:
    
    string value of char32 in UTF16 format
    
    Throws:
    
    IllegalArgumentException - Thrown if char32 is a invalid codepoint.
    
    Status:
    Stable ICU 2.1.
  - valueOf
```
public static String valueOf(String source,
                             int offset16)
```
    Convenience method corresponding to String.valueOf(codepoint at offset16). Returns a one or two char string containing the UTF-32 value in UTF16 format. If offset16 indexes a surrogate character, the whole supplementary codepoint will be returned. If a validity check is required, use UCharacter.isLegal(int) on the codepoint at offset16 before calling. The result returned will be a newly created String obtained by calling source.substring(..) with the appropriate indexes.
    
    Parameters:
    
    source - The input string.
    
    offset16 - The UTF16 index to the codepoint in source
    
    Returns:
    
    string value of char32 in UTF16 format
    
    Status:
    Stable ICU 2.1.
  - valueOf
```
public static String valueOf(StringBuffer source,
                             int offset16)
```
    Convenience method corresponding to StringBuffer.valueOf(codepoint at offset16). Returns a one or two char string containing the UTF-32 value in UTF16 format. If offset16 indexes a surrogate character, the whole supplementary codepoint will be returned. If a validity check is required, use UCharacter.isLegal(int) on the codepoint at offset16 before calling. The result returned will be a newly created String obtained by calling source.substring(..) with the appropriate indexes.
    
    Parameters:
    
    source - The input string buffer.
    
    offset16 - The UTF16 index to the codepoint in source
    
    Returns:
    
    string value of char32 in UTF16 format
    
    Status:
    Stable ICU 2.1.
  - valueOf
```
public static String valueOf(char[] source,
                             int start,
                             int limit,
                             int offset16)
```
    Convenience method. Returns a one or two char string containing the UTF-32 value in UTF16 format. If offset16 indexes a surrogate character, the whole supplementary codepoint will be returned, except when either the leading or trailing surrogate character lies out of the specified subarray. In the latter case, only the surrogate character within bounds will be returned. If a validity check is required, use UCharacter.isLegal(int) on the codepoint at offset16 before calling. The result returned will be a newly created String containing the relevant characters.
    
    Parameters:
    
    source - The input char array.
    
    start - Start index of the subarray
    
    limit - End index of the subarray
    
    offset16 - The UTF16 index to the codepoint in source relative to start
    
    Returns:
    
    string value of char32 in UTF16 format
    
    Status:
    Stable ICU 2.1.
  - findOffsetFromCodePoint
```
public static int findOffsetFromCodePoint(String source,
                                          int offset32)
```
    Returns the UTF-16 offset that corresponds to a UTF-32 offset. Used for random access. See the class description for notes on roundtripping.
    
    Parameters:
    
    source - The UTF-16 string
    
    offset32 - UTF-32 offset
    
    Returns:
    
    UTF-16 offset
    
    Throws:
    
    IndexOutOfBoundsException - If offset32 is out of bounds.
    
    Status:
    Stable ICU 2.1.
  - findOffsetFromCodePoint
```
public static int findOffsetFromCodePoint(StringBuffer source,
                                          int offset32)
```
    Returns the UTF-16 offset that corresponds to a UTF-32 offset. Used for random access. See the class description for notes on roundtripping.
    
    Parameters:
    
    source - The UTF-16 string buffer
    
    offset32 - UTF-32 offset
    
    Returns:
    
    UTF-16 offset
    
    Throws:
    
    IndexOutOfBoundsException - If offset32 is out of bounds.
    
    Status:
    Stable ICU 2.1.
  - findOffsetFromCodePoint
```
public static int findOffsetFromCodePoint(char[] source,
                                          int start,
                                          int limit,
                                          int offset32)
```
    Returns the UTF-16 offset that corresponds to a UTF-32 offset. Used for random access. See the class description for notes on roundtripping.
    
    Parameters:
    
    source - The UTF-16 char array whose substring is to be analysed
    
    start - Offset of the substring to be analysed
    
    limit - Offset of the substring to be analysed
    
    offset32 - UTF-32 offset relative to start
    
    Returns:
    
    UTF-16 offset relative to start
    
    Throws:
    
    IndexOutOfBoundsException - If offset32 is out of bounds.
    
    Status:
    Stable ICU 2.1.
  - findCodePointOffset
```
public static int findCodePointOffset(String source,
                                      int offset16)
```
    Returns the UTF-32 offset corresponding to the first UTF-32 boundary at or after the given UTF-16 offset. Used for random access. See the class description for notes on roundtripping.
    Note: If the UTF-16 offset is into the middle of a surrogate pair, then the UTF-32 offset of the lead of the pair is returned.
    To find the UTF-32 length of a string, use:
```
 len32 = countCodePoint(source, source.length());
 
```
    Parameters:
    
    source - Text to analyse
    
    offset16 - UTF-16 offset < source text length.
    
    Returns:
    
    UTF-32 offset
    
    Throws:
    
    IndexOutOfBoundsException - If offset16 is out of bounds.
    
    Status:
    Stable ICU 2.1.
  - findCodePointOffset
```
public static int findCodePointOffset(StringBuffer source,
                                      int offset16)
```
    Returns the UTF-32 offset corresponding to the first UTF-32 boundary at the given UTF-16 offset. Used for random access. See the class description for notes on roundtripping.
    Note: If the UTF-16 offset is into the middle of a surrogate pair, then the UTF-32 offset of the lead of the pair is returned.
    To find the UTF-32 length of a string, use:
```
 len32 = countCodePoint(source);
 
```
    Parameters:
    
    source - Text to analyse
    
    offset16 - UTF-16 offset < source text length.
    
    Returns:
    
    UTF-32 offset
    
    Throws:
    
    IndexOutOfBoundsException - If offset16 is out of bounds.
    
    Status:
    Stable ICU 2.1.
  - findCodePointOffset
```
public static int findCodePointOffset(char[] source,
                                      int start,
                                      int limit,
                                      int offset16)
```
    Returns the UTF-32 offset corresponding to the first UTF-32 boundary at the given UTF-16 offset. Used for random access. See the class description for notes on roundtripping.
    Note: If the UTF-16 offset is into the middle of a surrogate pair, then the UTF-32 offset of the lead of the pair is returned.
    To find the UTF-32 length of a substring, use:
```
 len32 = countCodePoint(source, start, limit);
 
```
    Parameters:
    
    source - Text to analyse
    
    start - Offset of the substring
    
    limit - Offset of the substring
    
    offset16 - UTF-16 relative to start
    
    Returns:
    
    UTF-32 offset relative to start
    
    Throws:
    
    IndexOutOfBoundsException - If offset16 is not within the range of start and limit.
    
    Status:
    Stable ICU 2.1.
  - append
```
public static StringBuffer append(StringBuffer target,
                                  int char32)
```
    Append a single UTF-32 value to the end of a StringBuffer. If a validity check is required, use UCharacter.isLegal(int) on char32 before calling.
    
    Parameters:
    
    target - The buffer to append to
    
    char32 - Value to append.
    
    Returns:
    
    the updated StringBuffer
    
    Throws:
    
    IllegalArgumentException - Thrown when char32 does not lie within the range of the Unicode codepoints
    
    Status:
    Stable ICU 2.1.
  - appendCodePoint
```
public static StringBuffer appendCodePoint(StringBuffer target,
                                           int cp)
```
    Cover JDK 1.5 APIs. Append the code point to the buffer and return the buffer as a convenience.
    
    Parameters:
    
    target - The buffer to append to
    
    cp - The code point to append
    
    Returns:
    
    the updated StringBuffer
    
    Throws:
    
    IllegalArgumentException - If cp is not a valid code point
    
    Status:
    Stable ICU 3.0.
  - append
```
public static int append(char[] target,
                         int limit,
                         int char32)
```
    Adds a codepoint to offset16 position of the argument char array.
    
    Parameters:
    
    target - Char array to be append with the new code point
    
    limit - UTF16 offset which the codepoint will be appended.
    
    char32 - Code point to be appended
    
    Returns:
    
    offset after char32 in the array.
    
    Throws:
    
    IllegalArgumentException - Thrown if there is not enough space for the append, or when char32 does not lie within the range of the Unicode codepoints.
    
    Status:
    Stable ICU 2.1.
  - countCodePoint
```
public static int countCodePoint(String source)
```
    Number of codepoints in a UTF16 String
    
    Parameters:
    
    source - UTF16 string
    
    Returns:
    
    number of codepoint in string
    
    Status:
    Stable ICU 2.1.
  - countCodePoint
```
public static int countCodePoint(StringBuffer source)
```
    Number of codepoints in a UTF16 String buffer
    
    Parameters:
    
    source - UTF16 string buffer
    
    Returns:
    
    number of codepoint in string
    
    Status:
    Stable ICU 2.1.
  - countCodePoint
```
public static int countCodePoint(char[] source,
                                 int start,
                                 int limit)
```
    Number of codepoints in a UTF16 char array substring
    
    Parameters:
    
    source - UTF16 char array
    
    start - Offset of the substring
    
    limit - Offset of the substring
    
    Returns:
    
    number of codepoint in the substring
    
    Throws:
    
    IndexOutOfBoundsException - If start and limit are not valid.
    
    Status:
    Stable ICU 2.1.
  - setCharAt
```
public static void setCharAt(StringBuffer target,
                             int offset16,
                             int char32)
```
    Set a code point into a UTF16 position. Adjusts target according if we are replacing a non-supplementary codepoint with a supplementary and vice versa.
    
    Parameters:
    
    target - Stringbuffer
    
    offset16 - UTF16 position to insert into
    
    char32 - Code point
    
    Status:
    Stable ICU 2.1.
  - setCharAt
```
public static int setCharAt(char[] target,
                            int limit,
                            int offset16,
                            int char32)
```
    Set a code point into a UTF16 position in a char array. Adjusts target according if we are replacing a non-supplementary codepoint with a supplementary and vice versa.
    
    Parameters:
    
    target - char array
    
    limit - numbers of valid chars in target, different from target.length. limit counts the number of chars in target that represents a string, not the size of array target.
    
    offset16 - UTF16 position to insert into
    
    char32 - code point
    
    Returns:
    
    new number of chars in target that represents a string
    
    Throws:
    
    IndexOutOfBoundsException - if offset16 is out of range
    
    Status:
    Stable ICU 2.1.
  - moveCodePointOffset
```
public static int moveCodePointOffset(String source,
                                      int offset16,
                                      int shift32)
```
    Shifts offset16 by the argument number of codepoints
    
    Parameters:
    
    source - string
    
    offset16 - UTF16 position to shift
    
    shift32 - number of codepoints to shift
    
    Returns:
    
    new shifted offset16
    
    Throws:
    
    IndexOutOfBoundsException - if the new offset16 is out of bounds.
    
    Status:
    Stable ICU 2.1.
  - moveCodePointOffset
```
public static int moveCodePointOffset(StringBuffer source,
                                      int offset16,
                                      int shift32)
```
    Shifts offset16 by the argument number of codepoints
    
    Parameters:
    
    source - String buffer
    
    offset16 - UTF16 position to shift
    
    shift32 - Number of codepoints to shift
    
    Returns:
    
    new shifted offset16
    
    Throws:
    
    IndexOutOfBoundsException - If the new offset16 is out of bounds.
    
    Status:
    Stable ICU 2.1.
  - moveCodePointOffset
```
public static int moveCodePointOffset(char[] source,
                                      int start,
                                      int limit,
                                      int offset16,
                                      int shift32)
```
    Shifts offset16 by the argument number of codepoints within a subarray.
    
    Parameters:
    
    source - Char array
    
    start - Position of the subarray to be performed on
    
    limit - Position of the subarray to be performed on
    
    offset16 - UTF16 position to shift relative to start
    
    shift32 - Number of codepoints to shift
    
    Returns:
    
    new shifted offset16 relative to start
    
    Throws:
    
    IndexOutOfBoundsException - If the new offset16 is out of bounds with respect to the subarray or the subarray bounds are out of range.
    
    Status:
    Stable ICU 2.1.
  - insert
```
public static StringBuffer insert(StringBuffer target,
                                  int offset16,
                                  int char32)
```
    Inserts char32 codepoint into target at the argument offset16. If the offset16 is in the middle of a supplementary codepoint, char32 will be inserted after the supplementary codepoint. The length of target increases by one if codepoint is non-supplementary, 2 otherwise.
    The overall effect is exactly as if the argument were converted to a string by the method valueOf(char) and the characters in that string were then inserted into target at the position indicated by offset16.
    
    The offset argument must be greater than or equal to 0, and less than or equal to the length of source.
    
    Parameters:
    
    target - String buffer to insert to
    
    offset16 - Offset which char32 will be inserted in
    
    char32 - Codepoint to be inserted
    
    Returns:
    
    a reference to target
    
    Throws:
    
    IndexOutOfBoundsException - Thrown if offset16 is invalid.
    
    Status:
    Stable ICU 2.1.
  - insert
```
public static int insert(char[] target,
                         int limit,
                         int offset16,
                         int char32)
```
    Inserts char32 codepoint into target at the argument offset16. If the offset16 is in the middle of a supplementary codepoint, char32 will be inserted after the supplementary codepoint. Limit increases by one if codepoint is non-supplementary, 2 otherwise.
    The overall effect is exactly as if the argument were converted to a string by the method valueOf(char) and the characters in that string were then inserted into target at the position indicated by offset16.
    
    The offset argument must be greater than or equal to 0, and less than or equal to the limit.
    
    Parameters:
    
    target - Char array to insert to
    
    limit - End index of the char array, limit <= target.length
    
    offset16 - Offset which char32 will be inserted in
    
    char32 - Codepoint to be inserted
    
    Returns:
    
    new limit size
    
    Throws:
    
    IndexOutOfBoundsException - Thrown if offset16 is invalid.
    
    Status:
    Stable ICU 2.1.
  - delete
```
public static StringBuffer delete(StringBuffer target,
                                  int offset16)
```
    Removes the codepoint at the specified position in this target (shortening target by 1 character if the codepoint is a non-supplementary, 2 otherwise).
    
    Parameters:
    
    target - String buffer to remove codepoint from
    
    offset16 - Offset which the codepoint will be removed
    
    Returns:
    
    a reference to target
    
    Throws:
    
    IndexOutOfBoundsException - Thrown if offset16 is invalid.
    
    Status:
    Stable ICU 2.1.
  - delete
```
public static int delete(char[] target,
                         int limit,
                         int offset16)
```
    Removes the codepoint at the specified position in this target (shortening target by 1 character if the codepoint is a non-supplementary, 2 otherwise).
    
    Parameters:
    
    target - String buffer to remove codepoint from
    
    limit - End index of the char array, limit <= target.length
    
    offset16 - Offset which the codepoint will be removed
    
    Returns:
    
    a new limit size
    
    Throws:
    
    IndexOutOfBoundsException - Thrown if offset16 is invalid.
    
    Status:
    Stable ICU 2.1.
  - indexOf
```
public static int indexOf(String source,
                          int char32)
```
    Returns the index within the argument UTF16 format Unicode string of the first occurrence of the argument codepoint. I.e., the smallest index i such that UTF16.charAt(source, i) == char32 is true.
    If no such character occurs in this string, then -1 is returned.
    
    Examples:
    UTF16.indexOf("abc", 'a') returns 0
    UTF16.indexOf("abc𐀀", 0x10000) returns 3
    UTF16.indexOf("abc𐀀", 0xd800) returns -1
    
    Note this method is provided as support to jdk 1.3, which does not support supplementary characters to its fullest.
    
    Parameters:
    
    source - UTF16 format Unicode string that will be searched
    
    char32 - Codepoint to search for
    
    Returns:
    
    the index of the first occurrence of the codepoint in the argument Unicode string, or -1 if the codepoint does not occur.
    
    Status:
    Stable ICU 2.6.
  - indexOf
```
public static int indexOf(String source,
                          String str)
```
    Returns the index within the argument UTF16 format Unicode string of the first occurrence of the argument string str. This method is implemented based on codepoints, hence a "lead surrogate character + trail surrogate character" is treated as one entity.e Hence if the str starts with trail surrogate character at index 0, a source with a leading a surrogate character before str found at in source will not have a valid match. Vice versa for lead surrogates that ends str. See example below.
    If no such string str occurs in this source, then -1 is returned.
    
    Examples:
    UTF16.indexOf("abc", "ab") returns 0
    UTF16.indexOf("abc𐀀", "𐀀") returns 3
    UTF16.indexOf("abc𐀀", "?") returns -1
    
    Note this method is provided as support to jdk 1.3, which does not support supplementary characters to its fullest.
    
    Parameters:
    
    source - UTF16 format Unicode string that will be searched
    
    str - UTF16 format Unicode string to search for
    
    Returns:
    
    the index of the first occurrence of the codepoint in the argument Unicode string, or -1 if the codepoint does not occur.
    
    Status:
    Stable ICU 2.6.
  - indexOf
```
public static int indexOf(String source,
                          int char32,
                          int fromIndex)
```
    Returns the index within the argument UTF16 format Unicode string of the first occurrence of the argument codepoint. I.e., the smallest index i such that:
    (UTF16.charAt(source, i) == char32 && i >= fromIndex) is true.
    If no such character occurs in this string, then -1 is returned.
    
    Examples:
    UTF16.indexOf("abc", 'a', 1) returns -1
    UTF16.indexOf("abc𐀀", 0x10000, 1) returns 3
    UTF16.indexOf("abc𐀀", 0xd800, 1) returns -1
    
    Note this method is provided as support to jdk 1.3, which does not support supplementary characters to its fullest.
    
    Parameters:
    
    source - UTF16 format Unicode string that will be searched
    
    char32 - Codepoint to search for
    
    fromIndex - The index to start the search from.
    
    Returns:
    
    the index of the first occurrence of the codepoint in the argument Unicode string at or after fromIndex, or -1 if the codepoint does not occur.
    
    Status:
    Stable ICU 2.6.
  - indexOf
```
public static int indexOf(String source,
                          String str,
                          int fromIndex)
```
    Returns the index within the argument UTF16 format Unicode string of the first occurrence of the argument string str. This method is implemented based on codepoints, hence a "lead surrogate character + trail surrogate character" is treated as one entity.e Hence if the str starts with trail surrogate character at index 0, a source with a leading a surrogate character before str found at in source will not have a valid match. Vice versa for lead surrogates that ends str. See example below.
    If no such string str occurs in this source, then -1 is returned.
    
    Examples:
    UTF16.indexOf("abc", "ab", 0) returns 0
    UTF16.indexOf("abc𐀀", "𐀀", 0) returns 3
    UTF16.indexOf("abc𐀀", "𐀀", 2) returns 3
    UTF16.indexOf("abc𐀀", "?", 0) returns -1
    
    Note this method is provided as support to jdk 1.3, which does not support supplementary characters to its fullest.
    
    Parameters:
    
    source - UTF16 format Unicode string that will be searched
    
    str - UTF16 format Unicode string to search for
    
    fromIndex - The index to start the search from.
    
    Returns:
    
    the index of the first occurrence of the codepoint in the argument Unicode string, or -1 if the codepoint does not occur.
    
    Status:
    Stable ICU 2.6.
  - lastIndexOf
```
public static int lastIndexOf(String source,
                              int char32)
```
    Returns the index within the argument UTF16 format Unicode string of the last occurrence of the argument codepoint. I.e., the index returned is the largest value i such that: UTF16.charAt(source, i) == char32 is true.
    Examples:
    UTF16.lastIndexOf("abc", 'a') returns 0
    UTF16.lastIndexOf("abc𐀀", 0x10000) returns 3
    UTF16.lastIndexOf("abc𐀀", 0xd800) returns -1
    
    source is searched backwards starting at the last character.
    Note this method is provided as support to jdk 1.3, which does not support supplementary characters to its fullest.
    
    Parameters:
    
    source - UTF16 format Unicode string that will be searched
    
    char32 - Codepoint to search for
    
    Returns:
    
    the index of the last occurrence of the codepoint in source, or -1 if the codepoint does not occur.
    
    Status:
    Stable ICU 2.6.
  - lastIndexOf
```
public static int lastIndexOf(String source,
                              String str)
```
    Returns the index within the argument UTF16 format Unicode string of the last occurrence of the argument string str. This method is implemented based on codepoints, hence a "lead surrogate character + trail surrogate character" is treated as one entity.e Hence if the str starts with trail surrogate character at index 0, a source with a leading a surrogate character before str found at in source will not have a valid match. Vice versa for lead surrogates that ends str. See example below.
    Examples:
    UTF16.lastIndexOf("abc", "a") returns 0
    UTF16.lastIndexOf("abc𐀀", "𐀀") returns 3
    UTF16.lastIndexOf("abc𐀀", "?") returns -1
    
    source is searched backwards starting at the last character.
    Note this method is provided as support to jdk 1.3, which does not support supplementary characters to its fullest.
    
    Parameters:
    
    source - UTF16 format Unicode string that will be searched
    
    str - UTF16 format Unicode string to search for
    
    Returns:
    
    the index of the last occurrence of the codepoint in source, or -1 if the codepoint does not occur.
    
    Status:
    Stable ICU 2.6.
  - lastIndexOf
```
public static int lastIndexOf(String source,
                              int char32,
                              int fromIndex)
```
    Returns the index within the argument UTF16 format Unicode string of the last occurrence of the argument codepoint, where the result is less than or equals to fromIndex.
    
    This method is implemented based on codepoints, hence a single surrogate character will not match a supplementary character.
    
    source is searched backwards starting at the last character starting at the specified index.
    
    Examples:
    UTF16.lastIndexOf("abc", 'c', 2) returns 2
    UTF16.lastIndexOf("abc", 'c', 1) returns -1
    UTF16.lastIndexOf("abc𐀀", 0x10000, 5) returns 3
    UTF16.lastIndexOf("abc𐀀", 0x10000, 3) returns 3
    UTF16.lastIndexOf("abc𐀀", 0xd800) returns -1
    
    Note this method is provided as support to jdk 1.3, which does not support supplementary characters to its fullest.
    
    Parameters:
    
    source - UTF16 format Unicode string that will be searched
    
    char32 - Codepoint to search for
    
    fromIndex - the index to start the search from. There is no restriction on the value of fromIndex. If it is greater than or equal to the length of this string, it has the same effect as if it were equal to one less than the length of this string: this entire string may be searched. If it is negative, it has the same effect as if it were -1: -1 is returned.
    
    Returns:
    
    the index of the last occurrence of the codepoint in source, or -1 if the codepoint does not occur.
    
    Status:
    Stable ICU 2.6.
  - lastIndexOf
```
public static int lastIndexOf(String source,
                              String str,
                              int fromIndex)
```
    Returns the index within the argument UTF16 format Unicode string of the last occurrence of the argument string str, where the result is less than or equals to fromIndex.
    
    This method is implemented based on codepoints, hence a "lead surrogate character + trail surrogate character" is treated as one entity. Hence if the str starts with trail surrogate character at index 0, a source with a leading a surrogate character before str found at in source will not have a valid match. Vice versa for lead surrogates that ends str.
    See example below.
    Examples:
    UTF16.lastIndexOf("abc", "c", 2) returns 2
    UTF16.lastIndexOf("abc", "c", 1) returns -1
    UTF16.lastIndexOf("abc𐀀", "𐀀", 5) returns 3
    UTF16.lastIndexOf("abc𐀀", "𐀀", 3) returns 3
    UTF16.lastIndexOf("abc𐀀", "?", 4) returns -1
    
    source is searched backwards starting at the last character.
    Note this method is provided as support to jdk 1.3, which does not support supplementary characters to its fullest.
    
    Parameters:
    
    source - UTF16 format Unicode string that will be searched
    
    str - UTF16 format Unicode string to search for
    
    fromIndex - the index to start the search from. There is no restriction on the value of fromIndex. If it is greater than or equal to the length of this string, it has the same effect as if it were equal to one less than the length of this string: this entire string may be searched. If it is negative, it has the same effect as if it were -1: -1 is returned.
    
    Returns:
    
    the index of the last occurrence of the codepoint in source, or -1 if the codepoint does not occur.
    
    Status:
    Stable ICU 2.6.
  - replace
```
public static String replace(String source,
                             int oldChar32,
                             int newChar32)
```
    Returns a new UTF16 format Unicode string resulting from replacing all occurrences of oldChar32 in source with newChar32. If the character oldChar32 does not occur in the UTF16 format Unicode string source, then source will be returned. Otherwise, a new String object is created that represents a codepoint sequence identical to the codepoint sequence represented by source, except that every occurrence of oldChar32 is replaced by an occurrence of newChar32.
    Examples:
    UTF16.replace("mesquite in your cellar", 'e', 'o');
    returns "mosquito in your collar"
    UTF16.replace("JonL", 'q', 'x');
    returns "JonL" (no change)
    UTF16.replace("Supplementary character 𐀀", 0x10000, '!');
    returns "Supplementary character !"
    UTF16.replace("Supplementary character 𐀀", 0xd800, '!');
    returns "Supplementary character 𐀀"
    
    Note this method is provided as support to jdk 1.3, which does not support supplementary characters to its fullest.
    
    Parameters:
    
    source - UTF16 format Unicode string which the codepoint replacements will be based on.
    
    oldChar32 - Non-zero old codepoint to be replaced.
    
    newChar32 - The new codepoint to replace oldChar32
    
    Returns:
    
    new String derived from source by replacing every occurrence of oldChar32 with newChar32, unless when no oldChar32 is found in source then source will be returned.
    
    Status:
    Stable ICU 2.6.
  - replace
```
public static String replace(String source,
                             String oldStr,
                             String newStr)
```
    Returns a new UTF16 format Unicode string resulting from replacing all occurrences of oldStr in source with newStr. If the string oldStr does not occur in the UTF16 format Unicode string source, then source will be returned. Otherwise, a new String object is created that represents a codepoint sequence identical to the codepoint sequence represented by source, except that every occurrence of oldStr is replaced by an occurrence of newStr.
    Examples:
    UTF16.replace("mesquite in your cellar", "e", "o");
    returns "mosquito in your collar"
    UTF16.replace("mesquite in your cellar", "mesquite", "cat");
    returns "cat in your cellar"
    UTF16.replace("JonL", "q", "x");
    returns "JonL" (no change)
    UTF16.replace("Supplementary character 𐀀", "𐀀", '!');
    returns "Supplementary character !"
    UTF16.replace("Supplementary character 𐀀", "?", '!');
    returns "Supplementary character 𐀀"
    
    Note this method is provided as support to jdk 1.3, which does not support supplementary characters to its fullest.
    
    Parameters:
    
    source - UTF16 format Unicode string which the replacements will be based on.
    
    oldStr - Non-zero-length string to be replaced.
    
    newStr - The new string to replace oldStr
    
    Returns:
    
    new String derived from source by replacing every occurrence of oldStr with newStr. When no oldStr is found in source, then source will be returned.
    
    Status:
    Stable ICU 2.6.
  - reverse
```
public static StringBuffer reverse(StringBuffer source)
```
    Reverses a UTF16 format Unicode string and replaces source's content with it. This method will reverse surrogate characters correctly, instead of blindly reversing every character.
    Examples:
    UTF16.reverse(new StringBuffer( "Supplementary characters 𐀀𐐁"))
    returns "𐐁𐀀 sretcarahc yratnemelppuS".
    
    Parameters:
    
    source - The source StringBuffer that contains UTF16 format Unicode string to be reversed
    
    Returns:
    
    a modified source with reversed UTF16 format Unicode string.
    
    Status:
    Stable ICU 2.6.
  - hasMoreCodePointsThan
```
public static boolean hasMoreCodePointsThan(String source,
                                            int number)
```
    Check if the string contains more Unicode code points than a certain number. This is more efficient than counting all code points in the entire string and comparing that number with a threshold. This function may not need to scan the string at all if the length is within a certain range, and never needs to count more than 'number + 1' code points. Logically equivalent to (countCodePoint(s) > number). A Unicode code point may occupy either one or two code units.
    
    Parameters:
    
    source - The input string.
    
    number - The number of code points in the string is compared against the 'number' parameter.
    
    Returns:
    
    boolean value for whether the string contains more Unicode code points than 'number'.
    
    Status:
    Stable ICU 2.4.
  - hasMoreCodePointsThan
```
public static boolean hasMoreCodePointsThan(char[] source,
                                            int start,
                                            int limit,
                                            int number)
```
    Check if the sub-range of char array, from argument start to limit, contains more Unicode code points than a certain number. This is more efficient than counting all code points in the entire char array range and comparing that number with a threshold. This function may not need to scan the char array at all if start and limit is within a certain range, and never needs to count more than 'number + 1' code points. Logically equivalent to (countCodePoint(source, start, limit) > number). A Unicode code point may occupy either one or two code units.
    
    Parameters:
    
    source - Array of UTF-16 chars
    
    start - Offset to substring in the source array for analyzing
    
    limit - Offset to substring in the source array for analyzing
    
    number - The number of code points in the string is compared against the 'number' parameter.
    
    Returns:
    
    boolean value for whether the string contains more Unicode code points than 'number'.
    
    Throws:
    
    IndexOutOfBoundsException - Thrown when limit < start
    
    Status:
    Stable ICU 2.4.
  - hasMoreCodePointsThan
```
public static boolean hasMoreCodePointsThan(StringBuffer source,
                                            int number)
```
    Check if the string buffer contains more Unicode code points than a certain number. This is more efficient than counting all code points in the entire string buffer and comparing that number with a threshold. This function may not need to scan the string buffer at all if the length is within a certain range, and never needs to count more than 'number + 1' code points. Logically equivalent to (countCodePoint(s) > number). A Unicode code point may occupy either one or two code units.
    
    Parameters:
    
    source - The input string buffer.
    
    number - The number of code points in the string buffer is compared against the 'number' parameter.
    
    Returns:
    
    boolean value for whether the string buffer contains more Unicode code points than 'number'.
    
    Status:
    Stable ICU 2.4.
  - newString
```
public static String newString(int[] codePoints,
                               int offset,
                               int count)
```
    Cover JDK 1.5 API. Create a String from an array of codePoints.
    
    Parameters:
    
    codePoints - The code array
    
    offset - The start of the text in the code point array
    
    count - The number of code points
    
    Returns:
    
    a String representing the code points between offset and count
    
    Throws:
    
    IllegalArgumentException - If an invalid code point is encountered
    
    IndexOutOfBoundsException - If the offset or count are out of bounds.
    
    Status:
    Stable ICU 3.0.
  - getSingleCodePoint
```
public static int getSingleCodePoint(CharSequence s)
```
    Utility for getting a code point from a CharSequence that contains exactly one code point.
    
    Parameters:
    
    s - to test
    
    Returns:
    
    the code point IF the string is non-null and consists of a single code point. otherwise returns -1.
    
    Status:
    Stable ICU 54.
  - compareCodePoint
```
public static int compareCodePoint(int codePoint,
                                   CharSequence s)
```
    Utility for comparing a code point to a string without having to create a new string. Returns the same results as a code point comparison of UTF16.valueOf(codePoint) and s.toString(). More specifically, if
```
 sc = new StringComparator(true,false,0);
 fast = UTF16.compareCodePoint(codePoint, charSequence)
 slower = sc.compare(UTF16.valueOf(codePoint), charSequence == null ? "" : charSequence.toString())
 
```
    then
```
 Integer.signum(fast) == Integer.signum(slower)
 
```
    Parameters:
    
    codePoint - to test
    
    s - to test
    
    Returns:
    
    equivalent of code point comparator comparing two strings.
    
    Status:
    Stable ICU 54.

Class UTF16

Nested Class Summary

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

SINGLE_CHAR_BOUNDARY

LEAD_SURROGATE_BOUNDARY

TRAIL_SURROGATE_BOUNDARY

CODEPOINT_MIN_VALUE

CODEPOINT_MAX_VALUE

SUPPLEMENTARY_MIN_VALUE

LEAD_SURROGATE_MIN_VALUE

TRAIL_SURROGATE_MIN_VALUE

LEAD_SURROGATE_MAX_VALUE

TRAIL_SURROGATE_MAX_VALUE

SURROGATE_MIN_VALUE

SURROGATE_MAX_VALUE

Method Detail

charAt

charAt

charAt

charAt

charAt

getCharCount

bounds

bounds

bounds

isSurrogate

isTrailSurrogate

isLeadSurrogate

getLeadSurrogate

getTrailSurrogate

valueOf

valueOf

valueOf

valueOf

findOffsetFromCodePoint

findOffsetFromCodePoint

findOffsetFromCodePoint

findCodePointOffset

findCodePointOffset

findCodePointOffset

append

appendCodePoint

append

countCodePoint

countCodePoint

countCodePoint

setCharAt

setCharAt

moveCodePointOffset

moveCodePointOffset

moveCodePointOffset

insert

insert

delete

delete

indexOf

indexOf

indexOf

indexOf

lastIndexOf

lastIndexOf

lastIndexOf

lastIndexOf

replace

replace

reverse

hasMoreCodePointsThan

hasMoreCodePointsThan

hasMoreCodePointsThan

newString

getSingleCodePoint

compareCodePoint