Can anyone explain the logic? I've tried many times

Question

How is the output 52?

public class Program
{
public static void main(String[] args) {
int x=0,y=0;
for(int j=1;j<5;j++){
if(++x>2&&++y>1) {
x++;
}
}
System.out.print(x+""+y);

}
}

Answer 1

ok well the first thing is to remember how java evaluates multiple conditions.

if (++x > 2 && ++y > 1)

if ++x > 2 is false, then java wont evaluate the other side, because if one side is false, then false && anything will always be false, hence the right side isnt evaluated (++y isnt incremented)

so with that in mind, if ++x > 2 is true, it will evaluate ++y > 1 and if that is also true, then the if branch is executed. now lets go through it:

j x y
------------
1 1 1
2 2 0
3 3 1
4 4 2
5

the inside of the if branch is executed when j = 4 because then both conditions of the if statement are true, so finally x is incremented from 4 to 5

so x is 5 and y is 2 if i did it correctly

Answer 2

@Edward: Nice Answer!

Answer 3

thanks @jay. and no problem @prathamesh. i also didnt know that when i first started learning java.

same goes for ||

if (x > 2 || y > 7)

if x> 2 is true, then the body is executed because
true || anything else is always true.

only evaluates the right side if x > 2 is false

Answer 4

Didn't know java evaluated conditions like this. Thanks for the explanation. You are awesome!