Overview | Package | Class | Use | Tree | Deprecated | Index | Help
PREV CLASS NEXT CLASS | FRAMES NO FRAMES
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD

## com.google.common.primitives
Class Chars

    java.lang.Object
      com.google.common.primitives.Chars

    @GwtCompatible(emulated=true)
    public final class Chars

extends Object

Static utility methods pertaining to `char` primitives, that are not already found in either `Character` or `Arrays`.

All the operations in this class treat `char` values strictly numerically; they are neither Unicode-aware nor locale-dependent.

Since:
  1.0
Author:
  Kevin Bourrillion

Field Summary
`static int` | `BYTES` The number of bytes required to represent a primitive `char` value.

Method Summary
`static List<Character>` | `asList(char... backingArray)` Returns a fixed-size list backed by the specified array, similar to `Arrays.asList(Object[])`.
`static char` | `checkedCast(long value)` Returns the `char` value that is equal to `value`, if possible.
`static int` | `compare(char a, char b)` Compares the two specified `char` values.
`static char[]` | `concat(char[]... arrays)` Returns the values from each provided array combined into a single array.
`static boolean` | `contains(char[] array, char target)` Returns `true` if `target` is present as an element anywhere in `array`.
`static char[]` | `ensureCapacity(char[] array, int minLength, int padding)` Returns an array containing the same values as `array`, but guaranteed to be of a specified minimum length.
`static char` | `fromByteArray(byte[] bytes)` Returns the `char` value whose big-endian representation is stored in the first 2 bytes of `bytes`; equivalent to `ByteBuffer.wrap(bytes).getChar()`.
`static char` | `fromBytes(byte b1, byte b2)` Returns the `char` value whose byte representation is the given 2 bytes, in big-endian order; equivalent to `Chars.fromByteArray(new byte[] {b1, b2})`.
`static int` | `hashCode(char value)` Returns a hash code for `value`; equal to the result of invoking `((Character) value).hashCode()`.
`static int` | `indexOf(char[] array, char target)` Returns the index of the first appearance of the value `target` in `array`.
`static int` | `indexOf(char[] array, char[] target)` Returns the start position of the first occurrence of the specified `target` within `array`, or `-1` if there is no such occurrence.
`static String` | `join(String separator, char... array)` Returns a string containing the supplied `char` values separated by `separator`.
`static int` | `lastIndexOf(char[] array, char target)` Returns the index of the last appearance of the value `target` in `array`.
`static Comparator<char[]>` | `lexicographicalComparator()` Returns a comparator that compares two `char` arrays lexicographically.
`static char` | `max(char... array)` Returns the greatest value present in `array`.
`static char` | `min(char... array)` Returns the least value present in `array`.
`static char` | `saturatedCast(long value)` Returns the `char` nearest in value to `value`.
`static char[]` | `toArray(Collection<Character> collection)` Copies a collection of `Character` instances into a new array of primitive `char` values.
`static byte[]` | `toByteArray(char value)` Returns a big-endian representation of `value` in a 2-element byte array; equivalent to `ByteBuffer.allocate(2).putChar(value).array()`.

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

Field Detail

### BYTES

    public static final int BYTES

  The number of bytes required to represent a primitive `char` value.

  See Also:
    Constant Field Values

Method Detail

### hashCode

    public static int hashCode(char value)

  Returns a hash code for `value`; equal to the result of invoking `((Character) value).hashCode()`.

  Parameters:
    `value` - a primitive `char` value
  Returns:
    a hash code for the value

### checkedCast

    public static char checkedCast(long value)

  Returns the `char` value that is equal to `value`, if possible.

  Parameters:
    `value` - any value in the range of the `char` type
  Returns:
    the `char` value that equals `value`
  Throws:
    `IllegalArgumentException` - if `value` is greater than `Character.MAX_VALUE` or less than `Character.MIN_VALUE`

### saturatedCast

    public static char saturatedCast(long value)

  Returns the `char` nearest in value to `value`.

  Parameters:
    `value` - any `long` value
  Returns:
    the same value cast to `char` if it is in the range of the `char` type, `Character.MAX_VALUE` if it is too large, or `Character.MIN_VALUE` if it is too small

### compare

    public static int compare(char a,
                              char b)

  Compares the two specified `char` values. The sign of the value returned is the same as that of `((Character) a).compareTo(b)`.

  Parameters:
    `a` - the first `char` to compare
    `b` - the second `char` to compare
  Returns:
    a negative value if `a` is less than `b`; a positive value if `a` is greater than `b`; or zero if they are equal

### contains

    public static boolean contains(char[] array,
                                   char target)

  Returns `true` if `target` is present as an element anywhere in `array`.

  Parameters:
    `array` - an array of `char` values, possibly empty
    `target` - a primitive `char` value
  Returns:
    `true` if `array[i] == target` for some value of `i`

### indexOf

    public static int indexOf(char[] array,
                              char target)

  Returns the index of the first appearance of the value `target` in `array`.

  Parameters:
    `array` - an array of `char` values, possibly empty
    `target` - a primitive `char` value
  Returns:
    the least index `i` for which `array[i] == target`, or `-1` if no such index exists.

### indexOf

    public static int indexOf(char[] array,
                              char[] target)

  Returns the start position of the first occurrence of the specified `target` within `array`, or `-1` if there is no such occurrence.

  More formally, returns the lowest index `i` such that `java.util.Arrays.copyOfRange(array, i, i + target.length)` contains exactly the same elements as `target`.

  Parameters:
    `array` - the array to search for the sequence `target`
    `target` - the array to search for as a sub-sequence of `array`

### lastIndexOf

    public static int lastIndexOf(char[] array,
                                  char target)

  Returns the index of the last appearance of the value `target` in `array`.

  Parameters:
    `array` - an array of `char` values, possibly empty
    `target` - a primitive `char` value
  Returns:
    the greatest index `i` for which `array[i] == target`, or `-1` if no such index exists.

### min

    public static char min(char... array)

  Returns the least value present in `array`.

  Parameters:
    `array` - a nonempty array of `char` values
  Returns:
    the value present in `array` that is less than or equal to every other value in the array
  Throws:
    `IllegalArgumentException` - if `array` is empty

### max

    public static char max(char... array)

  Returns the greatest value present in `array`.

  Parameters:
    `array` - a nonempty array of `char` values
  Returns:
    the value present in `array` that is greater than or equal to every other value in the array
  Throws:
    `IllegalArgumentException` - if `array` is empty

### concat

    public static char[] concat(char[]... arrays)

  Returns the values from each provided array combined into a single array. For example, `concat(new char[] {a, b}, new char[] {}, new char[] {c}` returns the array `{a, b, c}`.

  Parameters:
    `arrays` - zero or more `char` arrays
  Returns:
    a single array containing all the values from the source arrays, in order

### toByteArray

    @GwtIncompatible(value="doesn\'t work")
    public static byte[] toByteArray(char value)

  Returns a big-endian representation of `value` in a 2-element byte array; equivalent to `ByteBuffer.allocate(2).putChar(value).array()`. For example, the input value `'\\u5432'` would yield the byte array `{0x54, 0x32}`.

  If you need to convert and concatenate several values (possibly even of different types), use a shared `ByteBuffer` instance, or use `ByteStreams.newDataOutput()` to get a growable buffer.

### fromByteArray

    @GwtIncompatible(value="doesn\'t work")
    public static char fromByteArray(byte[] bytes)

  Returns the `char` value whose big-endian representation is stored in the first 2 bytes of `bytes`; equivalent to `ByteBuffer.wrap(bytes).getChar()`. For example, the input byte array `{0x54, 0x32}` would yield the `char` value `'\\u5432'`.

  Arguably, it's preferable to use `ByteBuffer`; that library exposes much more flexibility at little cost in readability.

  Throws:
    `IllegalArgumentException` - if `bytes` has fewer than 2 elements

### fromBytes

    @GwtIncompatible(value="doesn\'t work")
    public static char fromBytes(byte b1,
                                                      byte b2)

  Returns the `char` value whose byte representation is the given 2 bytes, in big-endian order; equivalent to `Chars.fromByteArray(new byte[] {b1, b2})`.

  Since:
    7.0

### ensureCapacity

    public static char[] ensureCapacity(char[] array,
                                        int minLength,
                                        int padding)

  Returns an array containing the same values as `array`, but guaranteed to be of a specified minimum length. If `array` already has a length of at least `minLength`, it is returned directly. Otherwise, a new array of size `minLength + padding` is returned, containing the values of `array`, and zeroes in the remaining places.

  Parameters:
    `array` - the source array
    `minLength` - the minimum length the returned array must guarantee
    `padding` - an extra amount to "grow" the array by if growth is necessary
  Returns:
    an array containing the values of `array`, with guaranteed minimum length `minLength`
  Throws:
    `IllegalArgumentException` - if `minLength` or `padding` is negative

### join

    public static String join(String separator,
                              char... array)

  Returns a string containing the supplied `char` values separated by `separator`. For example, `join("-", '1', '2', '3')` returns the string `"1-2-3"`.

  Parameters:
    `separator` - the text that should appear between consecutive values in the resulting string (but not at the start or end)
    `array` - an array of `char` values, possibly empty

### lexicographicalComparator

    public static Comparator<char[]> lexicographicalComparator()

  Returns a comparator that compares two `char` arrays lexicographically. That is, it compares, using `compare(char, char)`), the first pair of values that follow any common prefix, or when one array is a prefix of the other, treats the shorter array as the lesser. For example, `[] < ['a'] < ['a', 'b'] < ['b']`.

  The returned comparator is inconsistent with `Object.equals(Object)` (since arrays support only identity equality), but it is consistent with `Arrays.equals(char[], char[])`.

  Since:
    2.0
  See Also:
    Lexicographical order article at Wikipedia

### toArray

    public static char[] toArray(Collection<Character> collection)

  Copies a collection of `Character` instances into a new array of primitive `char` values.

  Elements are copied from the argument collection as if by `collection.toArray()`. Calling this method is as thread-safe as calling that method.

  Parameters:
    `collection` - a collection of `Character` objects
  Returns:
    an array containing the same values as `collection`, in the same order, converted to primitives
  Throws:
    `NullPointerException` - if `collection` or any of its elements is null

### asList

    public static List<Character> asList(char... backingArray)

  Returns a fixed-size list backed by the specified array, similar to `Arrays.asList(Object[])`. The list supports `List.set(int, Object)`, but any attempt to set a value to `null` will result in a `NullPointerException`.

  The returned list maintains the values, but not the identities, of `Character` objects written to or read from it. For example, whether `list.get(0) == list.get(0)` is true for the returned list is unspecified.

  Parameters:
    `backingArray` - the array to back the list
  Returns:
    a list view of the array

Overview | Package | Class | Use | Tree | Deprecated | Index | Help
PREV CLASS NEXT CLASS | FRAMES NO FRAMES
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD

Copyright © 2010-2011. All Rights Reserved.