6个位运算使用

1. 乘以2

int num = 10 << 1;
System.out.println(num);

2. 快速计算2的n次幂

int x = 1 << 10;
System.out.println(x); //1024

3. 校验奇数还是偶数

//校验奇偶数
int number = 11;
if((number & 1) == 0){
    
    
    System.out.println("偶数");
}else{
    
    
    System.out.println("奇数");
}

4. 交换两个变量

//交互两个变量
 int a = 1;
 int b = 2;
 a ^= b;
 b ^= a;
 a ^= b;
 System.out.println(a +" : "+b);

5. 找出只出现一次的数

//找出只出现一次的数
 Integer[] arr = new Integer[]{
    
    12,12,14,14,15};
 Integer[] res = new Integer[1];
 res[0] = 0;
 for (int i = 0; i < arr.length; i++) {
    
    
     res[0] ^= arr[i];
 }
 System.out.println(res[0]);

6. 对数字加密

//对数字加密
 int s = 1234567;
 int key = 6432;
 int encrypt = s ^ key;

 System.out.println("密文: "+encrypt);
 System.out.println("解密: "+(encrypt^key));