计算以整数n设置的位数。

//package com.nowjava;

/*来自 
 nowjava.com - 时  代  Java*/

public class Main {

    public static void main(String[] argv) throws Exception {

        int n = 2;

        System.out.println(countBits(n));

    }


    /**

     * Counts the number of bits set in an integer <i>n</i>.

     * 

     * @param n

     *            The integer to count.

     * @return The number of bits set in n.

     */

    public static int countBits(int n) {

        int total; // Holds the number of bits set.

        for (total = 0; n != 0; ++total) {/**来自 时 代 J a