BigInteger的“&”逻辑运算符等价

Question

if ((x & y)==0){ 
// do this... 
}

if ((x.compareTo(BigInteger.ZERO)==0)&&(y.compareTo(BigInteger.ZERO)==0)){ 
// do this...
}

import java.math.*;

public class mew {

public static void main (String[] args) {

BigInteger two = BigInteger.valueOf(2);
BigInteger num = two.pow(100);
BigInteger i = BigInteger.valueOf(0);

while (i.compareTo(num) < 0){
    BigInteger mask = num;

    while (mask.compareTo(BigInteger.ZERO) > 0){
            if ((mask.compareTo(BigInteger.ZERO)==0)&&(i.compareTo(BigInteger.ZERO)==0)){
             System.out.print("0");
             }
            else {
             System.out.print("1");
                }
             mask = mask.shiftRight(1);
                }
     System.out.println();
     i = i.add(BigInteger.valueOf(1));
          }

    }
}

Answer 1

相当于…

if ((x & y)==0){ 
    // do this... 
}

对于BigInteger是

if (x.and(y).equals(BigInteger.ZERO)) {
    // do this...
}

这两件事都不等于说“如果x和y都为零”。