What is the alternative for while(0) or while(1) in Java?

Question

I am solving an interview question which is to write a method that does the addition of two digits without using the + operator.

I understand the algorithm very well and I can do it easily in C.

Here is the algorithm and it works perfectly:

int add(int x, int y) {
int a, b;
do {
    a = x & y;           
    b = x ^ y; 
    x = a << 1; 
    y = b;
} while (a);
  return b;
}

I tried translating this code to Java, but this algorithm functions because a is going to become 000 at one point which in C will equal to False in the while loop. What is the alternative for that in Java?

Thanks.

Answer 1

You need to use a boolean for the condition in Java:

while (a != 0)

Edit (full code):

int add(int x, int y) {
int a, b;
do {
    a = x & y;           
    b = x ^ y; 
    x = a << 1; 
    y = b;
} while (a != 0);
return b;
}

Answer 2

Java does not - unlike C - interprete 0 as false . As stated in my comment you have to use a boolean expression such as:

while (a != 0)