Zig zag and zoom

[chichi_King]

Hey guys. Can somebody explain me the logic of this code please.


function mod15(n) {
    while (n >= 15) {
        n -= 15;
    }
    return n;
}

// This function should return a value from 0 to 9:
function mod9(n) {
    // While n is greater or equal to 9, subtract 9 from n:
    while(n >= 9) {
        n -= 9; 
    }
    return n;
}

// Don't change the following code:
while (true) {
    var time = hero.time;
    var x, y;
    if (time < 30) {
        y = 10 + 3 * mod15(time);
    } else {
        y = 20 + 3 * mod9(time);
    }
    x = 10 + time;
    hero.moveXY(x, y);
}

[bennypr0fane]

Maybe the explanations given here can help you:

Not an actual modulo operation?

[hetzenichtseistill] In this level in the desert where the return command is introduced (name displayed in screenshot: “Hetze nicht, sei still”) there’s a function referred to as “modulo operation” in the hints section: [modulo] However, the actual function is not performing a modulo calculation (calculating the rest of a division), there is only a subtraction: # Diese Funktion gibt einen Wert >= 0 und <30 zurück: def mod30(n): if n >= 30: return n - 30 else: return…

Code samples are in Python, but the underlying logic is discussed and should be the same. The key for me was that the defined function is actually only a subtraction, but becomes a modulo calculation by including it in a while-True loop. How exactly this mathematical operation helps you evade the missiles is something you’ll have to ask the developers
If you have any more questions, you’ll need to be more specific though.
Also, don’t include your question in the code formatting.