package code; //Java中所有的参数传递方式都是值传递 public class ValueTrans { public ValueTrans(int a,int b){ this.a = a; this.b = b; } int a; int b; public void exchange(){ int tmp; tmp = this.a; this.a = this.b; this.b = tmp; } public static void main(String[] args){ ValueTrans vt = new ValueTrans(6,9); vt.exchange(); System.out.println(vt.a); System.out.println(vt.b); } }