基础练习 - 数值交换

题目

             1 声明两个变量：int n1 = 10,n2= 20,要求将两个变量叫唤，最后输出n1为20,n2为10.
                     (扩展*: 不使用第三个变量如何交换)

解决方案

基本方法

private static void BasicMethod(){int n1 = 10;int n2 = 20;Console.WriteLine("n1={0}", n1);Console.WriteLine("n2={0}", n2);int tem = n1;Console.WriteLine("tem = n1,  此时tem = {0}", n1);n1 = n2;Console.WriteLine("n1  = n2,  此时 n1 = {0}", n2);n2 = tem;Console.WriteLine("n2  = tem, 此时 n2 = {0}", n2);Console.WriteLine("经过交换之后 n1 = {0},n2= {1}", n1, n2);Console.WriteLine("点击任意键结束程序...");Console.ReadLine();}

扩展方法

private static void ExpandMethod(){int n1 = 10;int n2 = 20;Console.WriteLine("n1={0}", n1);Console.WriteLine("n2={0}", n2);n1 = n1 + n2;Console.WriteLine("n1 = n1 + n2;此时n1={0}", n1);n2 = n1 - n2;Console.WriteLine("n2 = n1 - n2;此时n1={0},n2={1}", n1, n2);n1 = n1 - n2;Console.WriteLine("n1 = n1 - n2;此时n1={0},n2={1}", n1, n2);Console.WriteLine("经过交换之后 n1 = {0},n2= {1}", n1, n2);Console.WriteLine("点击任意键结束程序...");Console.ReadLine();}