Java---交换两个数的的位置

//位运算符
public class TestBit {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
         int a = 31;
         System.out.println(a << 3);
         //交换两个数的位置
         //方法一:缺点是需要定义一个新的变量
         int c = 10;
         int b = 20;
         System.out.println("开始:");
         System.out.println("c = " + c);
         System.out.println("b = " + b);
         int temp;
         temp = c;
         c = b;
         b = temp;
         System.out.println("此时结果为:");
         System.out.println("c = " + c  + "\n" + "b = " + b);
         //方法二;缺点:当b，c的值很大时就有可能溢出
         c = b + c;//c = 10 + 20
         b = c - b;// b = 10 + 20 - 20
         c = c - b;//c = 10 + 20 - 10
         System.out.println("此时结果为:");
         System.out.println("c = " + c);
         System.out.println("b = " + b);
         
         //方法三:优点是不创建新的变量
         c = c ^ b;
         b = c ^ b;//(c ^ b) ^ b == c
         c = c ^ b;//(c ^ b) ^ c == b
         System.out.println("此时结果为:");
         System.out.println("c = " + c);
         System.out.println("b = " + b);
	}

}