日期:2014-05-19  浏览次数:20819 次

为什么有这样的输出? 奇怪了?
Java code
import java.io.*;
import java.math.*;

public class Puncher {
    
    static int i,j;
    
    static void hole(int n)
    {
        int i;
        i = n+j;
        j= i+j;
        System.out.println("\n inside: i = "+i+" j = "+j);
    }
    
    public static void main(String argv[])
    {
        System.out.println("\n before: i = "+i+" j = " +j);
        hole(5);
        System.out.println("\n after: i = "+i+" j = " +j);
    }
}



我觉得输出应该是:
before: i = 0 j = 0

 inside: i = 5 j = 5

 after: i = 5 j = 5

然而跑了一下这个程序输出:

before: i = 0 j = 0

 inside: i = 5 j = 5

 after: i = 0 j = 5



------解决方案--------------------
你在hole()内部定义了一个局部变量i,改变的是局部变量,不是外面的那个i