Which costs more while looping; assignment or an if-statement?

Question

Consider the following 2 scenarios:

boolean b = false;
int i = 0;
while(i++ < 5) {
    b = true;
}

OR

boolean b = false;         


        

Answer 1

Relative to your barebones example (and perhaps your real application):

boolean b = false;
// .. other stuff, might change b
int i = 0;
// .. other stuff, might change i
b |= i < 5;
while(i++ < 5) {
    // .. stuff with i, possibly stuff with b, but no assignment to b
}

problem solved?

But really - it's going to be a question of the cost of your test (generally more than just if (boolean)) and the cost of your assignment (generally more than just primitive = x). If the test/assignment is expensive or your loop is long enough or you have high enough performance demands, you might want to break it into two parts - but all of those criteria require that you test how things perform. Of course, if your requirements are more demanding (say, b can flip back and forth), you might require a more complex solution.