位与运算符（&）

运算规则：两个数都转为二进制，然后从高位开始比较，如果两个数都为1则为1，否则为0。

比如：10&30.

10转换成二进制就是01010，30转换成二进制就是11110。从高位开始比较得到，得到01010，即10.

public class HelloWorld{
    public static void main(String[] args) {
    	   int one = 10 ;
           int two = 20 ;
           int three = 0 ;        
           three =one+two;        
           System.out.println(three);        
           //three=0;        
           three+=one;        
           System.out.println(three);        
           //three=0;        
           three-=one;        
           System.out.println(three);                
           //three=0;        
           three*=one;        
           System.out.println(three);                
           //three=0;        
           three/=one;        
           System.out.println(three);                
           //three=0;        
           three &=one;        
           System.out.println(three);                   	
           }
  }

厉害的一个一个敲空格，这排版跟shi一样

public class HelloWorld{    public static void main(String[] args) {	   int one = 10 ;        int two = 20 ;        int three = 0 ;        three =one+two;        System.out.println(three);        //three=0;        three+=one;        System.out.println(three);        //three=0;        three-=one;        System.out.println(three);                //three=0;        three*=one;        System.out.println(three);                //three=0;        three/=one;        System.out.println(three);                //three=0;        three &=one;        System.out.println(three);                   	}}

代码如下