Pls Explain how this results in 52 and not 85?

Question

int x = 0;
int y = 0;
for (int z = 1; z < 5; z++) {
if((++x > 2) && (++y > 1)) {
x++;
}
}
System.out.print(x + "" + y);

Answer 1

Just display the values of x and y at the beginning of each loop.

Remember: when you do

if(a && b) {

then you only enter the if when a and b both evaluate to true. That means if a evaluates to false you already know that you won't enter the if. So you don't need to evaluate b, and in fact you don't.

That means that with

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

you'll spend some iteration evaluating ++x but not evaluating ++y as ++x > 2 was false.
Therefore for some iterations x will be incrementing but y won't.

It is true that this is rather confusing. It demonstrates that when you evaluate conditions, they **really should not** modify the state of variables (also called, have side-effects). The conditions should be about knowing whether something is true or false, and **not at all** about changing anything to anything.