@GwtCompatible(emulated=true) public final class Chars extends Object
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.
See the Guava User Guide article on primitive utilities.
| Modifier and Type | Field and Description |
|---|---|
static int |
BYTES
The number of bytes required to represent a primitive
char value.
|
| Modifier and Type | Method and Description |
|---|---|
static List |
asList(char... backingArray)
Returns a fixed-size list backed by the specified array, similar to
Arrays.
|
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
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 |
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
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().
|
public static final int BYTES
char value.
public static int hashCode(char value)
value; equal to the result of invoking
((Character) value).hashCode().
value - a primitive
char value
public static char checkedCast(long value)
char value that is equal to
value, if possible.
value - any value in the range of the
char type
char value that equals
value
IllegalArgumentException - if
value is greater than
Character.MAX_VALUE or less than
Character.MIN_VALUE
public static char saturatedCast(long value)
char nearest in value to
value.
value - any
long value
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
public static int compare(char a,
char b)
char values. The sign of the value returned is the same as that of
((Character) a).compareTo(b).
Note for Java 7 and later: this method should be treated as deprecated; use the equivalent Character method instead.
a - the first
char to compare
b - the second
char to compare
a is less than
b; a positive value if
a is greater than
b; or zero if they are equal
public static boolean contains(char[] array,
char target)
true if
target is present as an element anywhere in
array.
array - an array of
char values, possibly empty
target - a primitive
char value
true if
array[i] == target for some value of
i
public static int indexOf(char[] array,
char target)
target in
array.
array - an array of
char values, possibly empty
target - a primitive
char value
i for which
array[i] == target, or
-1 if no such index exists.
public static int indexOf(char[] array,
char[] target)
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.
array - the array to search for the sequence
target
target - the array to search for as a sub-sequence of
array
public static int lastIndexOf(char[] array,
char target)
target in
array.
array - an array of
char values, possibly empty
target - a primitive
char value
i for which
array[i] == target, or
-1 if no such index exists.
public static char min(char... array)
array.
array - a
nonempty array of
char values
array that is less than or equal to every other value in the array
IllegalArgumentException - if
array is empty
public static char max(char... array)
array.
array - a
nonempty array of
char values
array that is greater than or equal to every other value in the array
IllegalArgumentException - if
array is empty
public static char[] concat(char[]... arrays)
concat(new char[] {a, b}, new char[] {}, new char[] {c} returns the array
{a, b, c}.
arrays - zero or more
char arrays
@GwtIncompatible(value="doesn\'t work") public static byte[] toByteArray(char value)
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 to get a growable buffer.
@GwtIncompatible(value="doesn\'t work") public static char fromByteArray(byte[] bytes)
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.
IllegalArgumentException - if
bytes has fewer than 2 elements
@GwtIncompatible(value="doesn\'t work") public static char fromBytes(byte b1, byte b2)
char value whose byte representation is the given 2 bytes, in big-endian order; equivalent to
Chars.fromByteArray(new byte[] {b1, b2}).
public static char[] ensureCapacity(char[] array,
int minLength,
int padding)
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.
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
array, with guaranteed minimum length
minLength
IllegalArgumentException - if
minLength or
padding is negative
public static Stringjoin(String separator, char... array)
char values separated by
separator. For example,
join("-", '1', '2', '3') returns the string
"1-2-3".
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
public static Comparator<char[]> lexicographicalComparator()
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 (since arrays support only identity equality), but it is consistent with Arrays.
public static char[] toArray(Collection<Character > collection)
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.
collection - a collection of
Character objects
collection, in the same order, converted to primitives
NullPointerException - if
collection or any of its elements is null
public static List<Character > asList(char... backingArray)
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.
backingArray - the array to back the list