Java Bit Count bitSizeForUnsignedValue(final int value)

Description

bit Size For Unsigned Value

License

Open Source License

Parameter

Parameter	Description
value	An integer value in [0,Integer.MAX_VALUE].

Exception

Parameter	Description
IllegalArgumentException	if the specified value is < 0.

Return

The number of bits required to store the specified value as an unsigned integer, i.e. a result in [1,31].

Declaration

public static int bitSizeForUnsignedValue(final int value) 

Method Source Code

//package com.java2s;
//License from project: Open Source License 

public class Main {
    /**/*  ww  w . jav  a 2s. c  o m*/
     * @param value
     *            An integer value in [0,Integer.MAX_VALUE].
     * @return The number of bits required to store the specified value as an unsigned integer, i.e. a result in [1,31].
     * @throws IllegalArgumentException
     *             if the specified value is < 0.
     */
    public static int bitSizeForUnsignedValue(final int value) {
        if (value > 0) {
            return 32 - Integer.numberOfLeadingZeros(value);
        } else {
            if (value == 0) {
                return 1;
            } else {
                throw new IllegalArgumentException("unsigned value [" + value + "] must be >= 0");
            }
        }
    }

    /**
     * @param value
     *            An integer value in [0,Long.MAX_VALUE].
     * @return The number of bits required to store the specified value as an unsigned integer, i.e. a result in [1,63].
     * @throws IllegalArgumentException
     *             if the specified value is < 0.
     */
    public static int bitSizeForUnsignedValue(final long value) {
        if (value > 0) {
            return 64 - Long.numberOfLeadingZeros(value);
        } else {
            if (value == 0) {
                return 1;
            } else {
                throw new IllegalArgumentException("unsigned value [" + value + "] must be >= 0");
            }
        }
    }
}

Related

1. bitLength(byte[] bytes)
2. bitLength(final int byteLength)
3. bitLength(int num)
4. bitLength(int value)
5. bitSizeForSignedValue(final int value)
6. countBits (long v)
7. countBits(byte num)
8. countBits(final int intValue)
9. countBits(int i)