com.google.common.primitives
Class UnsignedInts

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

@Beta
@GwtCompatible
public final class UnsignedInts
extends Object

Static utility methods pertaining to int primitives that interpret values as unsigned (that is, any negative value x is treated as the positive value 2^32 + x). The methods for which signedness is not an issue are in Ints, as well as signed versions of methods for which signedness is an issue.

In addition, this class provides several static methods for converting an int to a String and a String to an int that treat the int as an unsigned number.

Users of these utilities must be extremely careful not to mix up signed and unsigned int values. When possible, it is recommended that the UnsignedInteger wrapper class be used, at a small efficiency penalty, to enforce the distinction in the type system.

Since:

11.0

Author:

Louis Wasserman

Method Summary

static int	compare(int a, int b) Compares the two specified int values, treating them as unsigned values between 0 and 2^32 - 1 inclusive.
static int	divide(int dividend, int divisor) Returns dividend / divisor, where the dividend and divisor are treated as unsigned 32-bit quantities.
static String	join(String separator, int... array) Returns a string containing the supplied unsigned int values separated by separator.
static Comparator<int[]>	lexicographicalComparator() Returns a comparator that compares two arrays of unsigned int values lexicographically.
static int	max(int... array) Returns the greatest value present in array, treating values as unsigned.
static int	min(int... array) Returns the least value present in array, treating values as unsigned.
static int	parseUnsignedInt(String s) Returns the unsigned int value represented by the given decimal string.
static int	parseUnsignedInt(String string, int radix) Returns the unsigned int value represented by a string with the given radix.
static int	remainder(int dividend, int divisor) Returns dividend % divisor, where the dividend and divisor are treated as unsigned 32-bit quantities.
static long	toLong(int value) Returns the value of the given int as a long, when treated as unsigned.
static String	toString(int x) Returns a string representation of x, where x is treated as unsigned.
static String	toString(int x, int radix) Returns a string representation of x for the given radix, where x is treated as unsigned.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

compare

public static int compare(int a,
                          int b)

Compares the two specified int values, treating them as unsigned values between 0 and 2^32 - 1 inclusive.

Parameters:

a - the first unsigned int to compare

b - the second unsigned 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

toLong

public static long toLong(int value)

Returns the value of the given int as a long, when treated as unsigned.

min

public static int min(int... array)

Returns the least value present in array, treating values as unsigned.

Parameters:

array - a nonempty array of unsigned int values

Returns:

the value present in array that is less than or equal to every other value in the array according to compare(int, int)

Throws:

IllegalArgumentException - if array is empty

max

public static int max(int... array)

Returns the greatest value present in array, treating values as unsigned.

Parameters:

array - a nonempty array of unsigned int values

Returns:

the value present in array that is greater than or equal to every other value in the array according to compare(int, int)

Throws:

IllegalArgumentException - if array is empty

join

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

Returns a string containing the supplied unsigned 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 unsigned int values, possibly empty

lexicographicalComparator

public static Comparator<int[]> lexicographicalComparator()

Returns a comparator that compares two arrays of unsigned int values 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] < [1 << 31].

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

See Also:

Lexicographical order article at Wikipedia

divide

public static int divide(int dividend,
                         int divisor)

Returns dividend / divisor, where the dividend and divisor are treated as unsigned 32-bit quantities.

Parameters:

dividend - the dividend (numerator)

divisor - the divisor (denominator)

Throws:

ArithmeticException - if divisor is 0

remainder

public static int remainder(int dividend,
                            int divisor)

Returns dividend % divisor, where the dividend and divisor are treated as unsigned 32-bit quantities.

Parameters:

dividend - the dividend (numerator)

divisor - the divisor (denominator)

Throws:

ArithmeticException - if divisor is 0

parseUnsignedInt

public static int parseUnsignedInt(String s)

Returns the unsigned int value represented by the given decimal string.

Throws:

NumberFormatException - if the string does not contain a valid unsigned integer, or if the value represented is too large to fit in an unsigned int.

NullPointerException - if s is null

parseUnsignedInt

public static int parseUnsignedInt(String string,
                                   int radix)

Returns the unsigned int value represented by a string with the given radix.

Parameters:

string - the string containing the unsigned integer representation to be parsed.

radix - the radix to use while parsing s; must be between Character.MIN_RADIX and Character.MAX_RADIX.

Throws:

NumberFormatException - if the string does not contain a valid unsigned int, or if supplied radix is invalid.

toString

public static String toString(int x)

Returns a string representation of x, where x is treated as unsigned.

toString

public static String toString(int x,
                              int radix)

Returns a string representation of x for the given radix, where x is treated as unsigned.

Parameters:

x - the value to convert to a string.

radix - the radix to use while working with x

Throws:

IllegalArgumentException - if radix is not between Character.MIN_RADIX and Character.MAX_RADIX.