Ints (Guava: Google Core Libraries for Java 23.0 API)

java.lang.Object
- com.google.common.primitives.Ints

```
@GwtCompatible
public final class Ints
extends Object
```
Static utility methods pertaining to int primitives, that are not already found in either Integer or Arrays.
See the Guava User Guide article on primitive utilities.

Since:

1.0

Author:

Kevin Bourrillion

Field Summary

Fields
Modifier and Type	Field and Description
`static int`	`BYTES` The number of bytes required to represent a primitive `int` value.
`static int`	`MAX_POWER_OF_TWO` The largest power of two that can be represented as an `int`.

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static List<Integer>`	`asList(int... backingArray)` Returns a fixed-size list backed by the specified array, similar to `Arrays.asList(Object[])`.
`static int`	`checkedCast(long value)` Returns the `int` value that is equal to `value`, if possible.
`static int`	`compare(int a, int b)` Compares the two specified `int` values.
`static int[]`	`concat(int[]... arrays)` Returns the values from each provided array combined into a single array.
`static int`	`constrainToRange(int value, int min, int max)` Returns the value nearest to `value` which is within the closed range `[min..max]`.
`static boolean`	`contains(int[] array, int target)` Returns `true` if `target` is present as an element anywhere in `array`.
`static int[]`	`ensureCapacity(int[] array, int minLength, int padding)` Returns an array containing the same values as `array`, but guaranteed to be of a specified minimum length.
`static int`	`fromByteArray(byte[] bytes)` Returns the `int` value whose big-endian representation is stored in the first 4 bytes of `bytes`; equivalent to `ByteBuffer.wrap(bytes).getInt()`.
`static int`	`fromBytes(byte b1, byte b2, byte b3, byte b4)` Returns the `int` value whose byte representation is the given 4 bytes, in big-endian order; equivalent to `Ints.fromByteArray(new byte[] {b1, b2, b3, b4})`.
`static int`	`hashCode(int value)` Returns a hash code for `value`; equal to the result of invoking `((Integer) value).hashCode()`.
`static int`	`indexOf(int[] array, int target)` Returns the index of the first appearance of the value `target` in `array`.
`static int`	`indexOf(int[] array, int[] 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, int... array)` Returns a string containing the supplied `int` values separated by `separator`.
`static int`	`lastIndexOf(int[] array, int target)` Returns the index of the last appearance of the value `target` in `array`.
`static Comparator<int[]>`	`lexicographicalComparator()` Returns a comparator that compares two `int` arrays lexicographically.
`static int`	`max(int... array)` Returns the greatest value present in `array`.
`static int`	`min(int... array)` Returns the least value present in `array`.
`static int`	`saturatedCast(long value)` Returns the `int` nearest in value to `value`.
`static Converter<String,Integer>`	`stringConverter()` Returns a serializable converter object that converts between strings and integers using `Integer.decode(java.lang.String)` and `Integer.toString()`.
`static int[]`	`toArray(Collection<? extends Number> collection)` Returns an array containing each value of `collection`, converted to a `int` value in the manner of `Number.intValue()`.
`static byte[]`	`toByteArray(int value)` Returns a big-endian representation of `value` in a 4-element byte array; equivalent to `ByteBuffer.allocate(4).putInt(value).array()`.
`static Integer`	`tryParse(String string)` Parses the specified string as a signed decimal integer value.
`static Integer`	`tryParse(String string, int radix)` Parses the specified string as a signed integer value using the specified radix.

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 int value.
    Java 8 users: use Integer.BYTES instead.
    
    See Also:
    
    Constant Field Values
  - MAX_POWER_OF_TWO
```
public static final int MAX_POWER_OF_TWO
```
    The largest power of two that can be represented as an int.
    
    Since:
    
    10.0
    
    See Also:
    
    Constant Field Values
- Method Detail
  - hashCode
```
public static int hashCode(int value)
```
    Returns a hash code for value; equal to the result of invoking ((Integer) value).hashCode().
    Java 8 users: use Integer.hashCode(int) instead.
    
    Parameters:
    
    value - a primitive int value
    
    Returns:
    
    a hash code for the value
  - checkedCast
```
public static int checkedCast(long value)
```
    Returns the int value that is equal to value, if possible.
    
    Parameters:
    
    value - any value in the range of the int type
    
    Returns:
    
    the int value that equals value
    
    Throws:
    
    IllegalArgumentException - if value is greater than Integer.MAX_VALUE or less than Integer.MIN_VALUE
  - saturatedCast
```
public static int saturatedCast(long value)
```
    Returns the int nearest in value to value.
    
    Parameters:
    
    value - any long value
    
    Returns:
    
    the same value cast to int if it is in the range of the int type, Integer.MAX_VALUE if it is too large, or Integer.MIN_VALUE if it is too small
  - compare
```
public static int compare(int a,
                          int b)
```
    Compares the two specified int values. The sign of the value returned is the same as that of ((Integer) a).compareTo(b).
    Note for Java 7 and later: this method should be treated as deprecated; use the equivalent Integer.compare(int, int) method instead.
    
    Parameters:
    
    a - the first int to compare
    
    b - the second int 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(int[] array,
                               int target)
```
    Returns true if target is present as an element anywhere in array.
    
    Parameters:
    
    array - an array of int values, possibly empty
    
    target - a primitive int value
    
    Returns:
    
    true if array[i] == target for some value of i
  - indexOf
```
public static int indexOf(int[] array,
                          int target)
```
    Returns the index of the first appearance of the value target in array.
    
    Parameters:
    
    array - an array of int values, possibly empty
    
    target - a primitive int value
    
    Returns:
    
    the least index i for which array[i] == target, or -1 if no such index exists.
  - indexOf
```
public static int indexOf(int[] array,
                          int[] 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 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(int[] array,
                              int target)
```
    Returns the index of the last appearance of the value target in array.
    
    Parameters:
    
    array - an array of int values, possibly empty
    
    target - a primitive int value
    
    Returns:
    
    the greatest index i for which array[i] == target, or -1 if no such index exists.
  - min
```
public static int min(int... array)
```
    Returns the least value present in array.
    
    Parameters:
    
    array - a nonempty array of int 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 int max(int... array)
```
    Returns the greatest value present in array.
    
    Parameters:
    
    array - a nonempty array of int 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
  - constrainToRange
```
@Beta
public static int constrainToRange(int value,
                                         int min,
                                         int max)
```
    Returns the value nearest to value which is within the closed range [min..max].
    If value is within the range [min..max], value is returned unchanged. If value is less than min, min is returned, and if value is greater than max, max is returned.
    
    Parameters:
    
    value - the int value to constrain
    
    min - the lower bound (inclusive) of the range to constrain value to
    
    max - the upper bound (inclusive) of the range to constrain value to
    
    Throws:
    
    IllegalArgumentException - if min > max
    
    Since:
    
    21.0
  - concat
```
public static int[] concat(int[]... arrays)
```
    Returns the values from each provided array combined into a single array. For example, concat(new int[] {a, b}, new int[] {}, new int[] {c} returns the array {a, b, c}.
    
    Parameters:
    
    arrays - zero or more int arrays
    
    Returns:
    
    a single array containing all the values from the source arrays, in order
  - toByteArray
```
public static byte[] toByteArray(int value)
```
    Returns a big-endian representation of value in a 4-element byte array; equivalent to ByteBuffer.allocate(4).putInt(value).array(). For example, the input value 0x12131415 would yield the byte array {0x12, 0x13, 0x14, 0x15}.
    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
```
public static int fromByteArray(byte[] bytes)
```
    Returns the int value whose big-endian representation is stored in the first 4 bytes of bytes; equivalent to ByteBuffer.wrap(bytes).getInt(). For example, the input byte array {0x12, 0x13, 0x14, 0x15, 0x33} would yield the int value 0x12131415.
    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 4 elements
  - fromBytes
```
public static int fromBytes(byte b1,
                            byte b2,
                            byte b3,
                            byte b4)
```
    Returns the int value whose byte representation is the given 4 bytes, in big-endian order; equivalent to Ints.fromByteArray(new byte[] {b1, b2, b3, b4}).
    
    Since:
    
    7.0
  - stringConverter
```
@Beta
public static Converter<String,Integer> stringConverter()
```
    Returns a serializable converter object that converts between strings and integers using Integer.decode(java.lang.String) and Integer.toString(). The returned converter throws NumberFormatException if the input string is invalid.
    Warning: please see Integer.decode(java.lang.String) to understand exactly how strings are parsed. For example, the string "0123" is treated as octal and converted to the value 83.
    
    Since:
    
    16.0
  - ensureCapacity
```
public static int[] ensureCapacity(int[] 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,
                          int... array)
```
    Returns a string containing the supplied int 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 int values, possibly empty
  - lexicographicalComparator
```
public static Comparator<int[]> lexicographicalComparator()
```
    Returns a comparator that compares two int arrays lexicographically. That is, it compares, using compare(int, int)), 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, [] < [1] < [1, 2] < [2].
    The returned comparator is inconsistent with Object.equals(Object) (since arrays support only identity equality), but it is consistent with Arrays.equals(int[], int[]).
    
    Since:
    
    2.0
  - toArray
```
public static int[] toArray(Collection<? extends Number> collection)
```
    Returns an array containing each value of collection, converted to a int value in the manner of Number.intValue().
    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 Number instances
    
    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
    
    Since:
    
    1.0 (parameter was Collection<Integer> before 12.0)
  - asList
```
public static List<Integer> asList(int... 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 Integer 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
  - tryParse
```
@Beta
 @Nullable
 @CheckForNull
public static Integer tryParse(String string)
```
    Parses the specified string as a signed decimal integer value. The ASCII character '-' ('\u002D') is recognized as the minus sign.
    Unlike Integer.parseInt(String), this method returns null instead of throwing an exception if parsing fails. Additionally, this method only accepts ASCII digits, and returns null if non-ASCII digits are present in the string.
    Note that strings prefixed with ASCII '+' are rejected, even under JDK 7, despite the change to Integer.parseInt(String) for that version.
    
    Parameters:
    
    string - the string representation of an integer value
    
    Returns:
    
    the integer value represented by string, or null if string has a length of zero or cannot be parsed as an integer value
    
    Since:
    
    11.0
  - tryParse
```
@Beta
 @Nullable
 @CheckForNull
public static Integer tryParse(String string,
                                                               int radix)
```
    Parses the specified string as a signed integer value using the specified radix. The ASCII character '-' ('\u002D') is recognized as the minus sign.
    Unlike Integer.parseInt(String, int), this method returns null instead of throwing an exception if parsing fails. Additionally, this method only accepts ASCII digits, and returns null if non-ASCII digits are present in the string.
    Note that strings prefixed with ASCII '+' are rejected, even under JDK 7, despite the change to Integer.parseInt(String, int) for that version.
    
    Parameters:
    
    string - the string representation of an integer value
    
    radix - the radix to use when parsing
    
    Returns:
    
    the integer value represented by string using radix, or null if string has a length of zero or cannot be parsed as an integer value
    
    Throws:
    
    IllegalArgumentException - if radix < Character.MIN_RADIX or radix > Character.MAX_RADIX
    
    Since:
    
    19.0

Class Ints

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

BYTES

MAX_POWER_OF_TWO

Method Detail

hashCode

checkedCast

saturatedCast

compare

contains

indexOf

indexOf

lastIndexOf

min

max

constrainToRange

concat

toByteArray

fromByteArray

fromBytes

stringConverter

ensureCapacity

join

lexicographicalComparator

toArray

asList

tryParse

tryParse