交换变量的值

 1 #region 1 利用第三方变量
 2             int a = 10;
 3             int b = 20;
 4             Console.WriteLine("交换前的值：a={0},b={1}", a, b);
 5             Console.ReadKey();
 6             int temp = a;
 7             a = b;
 8             b = temp;
 9             Console.WriteLine("交换后的值：a={0},b={1}", a, b);
10             Console.ReadKey();
11             #endregion

 1 #region 2 不利用三方变量 (加减法)
 2             int a = 10;
 3             int b = 20;
 4             Console.WriteLine("交换前的值：a={0},b={1}", a, b);
 5             Console.ReadKey();
 6             a = a + b;   //30 
 7             b = a - b;   //10
 8             a = a - b;   //20
 9             Console.WriteLine("交换后的值：a={0},b={1}", a, b);
10             Console.ReadKey();
11             #endregion

 1 /*
 2              *分析：数字变为二进制在进行异或运算[0^1 = 1 ,0^0=0 1^1=0]
 3              *10  ==> 01001   ==>a
 4              *20  ==> 10100   ==>b
 5              * a^b
 6              * 01001
 7              * 10100
 8              * 11101   ==> a
 9              * 10100
10              * 01001   ==>b(10)
11              * 11101
12              * 10100   ==>a(20)
13              */
14             int a = 10;
15             int b = 20;
16             Console.WriteLine("交换前：a={0},b={1}", a, b);
17             Console.ReadKey();
18             a = a ^ b;
19             b = a ^ b;
20             a = a ^ b;
21             Console.WriteLine("交换后：a={0},b={1}", a, b);
22             Console.ReadKey();