Class UnsignedInts

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

See the Guava User Guide article on unsigned primitive utilities.

Since:
11.0
Author:
Louis Wasserman

  • Method Summary

    Modifier and Type
    Method
    Description
    static int
    checkedCast(long value)
    Returns the int value that, when treated as unsigned, is equal to value, if possible.
    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
    decode(String stringValue)
    Returns the unsigned int value represented by the given string.
    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 int
    saturatedCast(long value)
    Returns the int value that, when treated as unsigned, is nearest in value to value.
    static void
    sort(int[] array)
    Sorts the array, treating its elements as unsigned 32-bit integers.
    static void
    sort(int[] array, int fromIndex, int toIndex)
    Sorts the array between fromIndex inclusive and toIndex exclusive, treating its elements as unsigned 32-bit integers.
    static void
    sortDescending(int[] array)
    Sorts the elements of array in descending order, interpreting them as unsigned 32-bit integers.
    static void
    sortDescending(int[] array, int fromIndex, int toIndex)
    Sorts the elements of array between fromIndex inclusive and toIndex exclusive in descending order, interpreting them as unsigned 32-bit integers.
    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 Details

    • 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.

      Note: this method is now unnecessary and should be treated as deprecated; use the equivalent Integer.compareUnsigned(int, int) method instead.

      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.

      Java 8+ users: use Integer.toUnsignedLong(int) instead.

    • checkedCast

      public static int checkedCast(long value)
      Returns the int value that, when treated as unsigned, is equal to value, if possible.
      Parameters:
      value - a value between 0 and 232-1 inclusive
      Returns:
      the int value that, when treated as unsigned, equals value
      Throws:
      IllegalArgumentException - if value is negative or greater than or equal to 232
      Since:
      21.0

    • saturatedCast

      public static int saturatedCast(long value)
      Returns the int value that, when treated as unsigned, is nearest in value to value.
      Parameters:
      value - any long value
      Returns:
      2^32 - 1 if value >= 2^32, 0 if value <= 0, and value cast to int otherwise
      Since:
      21.0

    • 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[]).

    • sort

      public static void sort(int[] array)
      Sorts the array, treating its elements as unsigned 32-bit integers.
      Since:
      23.1

    • sort

      public static void sort(int[] array, int fromIndex, int toIndex)
      Sorts the array between fromIndex inclusive and toIndex exclusive, treating its elements as unsigned 32-bit integers.
      Since:
      23.1

    • sortDescending

      public static void sortDescending(int[] array)
      Sorts the elements of array in descending order, interpreting them as unsigned 32-bit integers.
      Since:
      23.1

    • sortDescending

      public static void sortDescending(int[] array, int fromIndex, int toIndex)
      Sorts the elements of array between fromIndex inclusive and toIndex exclusive in descending order, interpreting them as unsigned 32-bit integers.
      Since:
      23.1

    • divide

      public static int divide(int dividend, int divisor)
      Returns dividend / divisor, where the dividend and divisor are treated as unsigned 32-bit quantities.

      Java 8+ users: use Integer.divideUnsigned(int, int) instead.

      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.

      Java 8+ users: use Integer.remainderUnsigned(int, int) instead.

      Parameters:
      dividend - the dividend (numerator)
      divisor - the divisor (denominator)
      Throws:
      ArithmeticException - if divisor is 0

    • decode

      @CanIgnoreReturnValue public static int decode(String stringValue)
      Returns the unsigned int value represented by the given string.

      Accepts a decimal, hexadecimal, or octal number given by specifying the following prefix:

      • 0xHexDigits
      • 0XHexDigits
      • #HexDigits
      • 0OctalDigits
      Throws:
      NumberFormatException - if the string does not contain a valid unsigned int value
      Since:
      13.0

    • parseUnsignedInt

      @CanIgnoreReturnValue public static int parseUnsignedInt(String s)
      Returns the unsigned int value represented by the given decimal string.

      Java 8+ users: use Integer.parseUnsignedInt(String) instead.

      Throws:
      NumberFormatException - if the string does not contain a valid unsigned int value
      NullPointerException - if s is null (in contrast to Integer.parseInt(String))

    • parseUnsignedInt

      @CanIgnoreReturnValue public static int parseUnsignedInt(String string, int radix)
      Returns the unsigned int value represented by a string with the given radix.

      Java 8+ users: use Integer.parseUnsignedInt(String, int) instead.

      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.
      NullPointerException - if s is null (in contrast to Integer.parseInt(String))

    • toString

      public static String toString(int x)
      Returns a string representation of x, where x is treated as unsigned.

      Java 8+ users: use Integer.toUnsignedString(int) instead.

    • 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.

      Java 8+ users: use Integer.toUnsignedString(int, int) instead.

      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.