Question

I’m trying to make a basic (non animated) slot machine but am getting an error with stack size.

I’m hoping some one can explain what the cause is =/

My Error :

Uncaught RangeError: Maximum call stack size exceeded

Code:

    window.requestAnimFrame = (function(){
      return  window.requestAnimationFrame       || 
              window.webkitRequestAnimationFrame || 
              window.mozRequestAnimationFrame    || 
              window.oRequestAnimationFrame      || 
              window.msRequestAnimationFrame     || 
              function( callback,  element){
                window.setTimeout(callback, 1000 / 60);
              };
    })();
var img_array = new Array('fire','life','lightning','rain','snow','sound','sun');


function roll(start_time){
var seconds_passed = new Date().getTime() / 1000 - start_time ;

if(seconds_passed < 3){
    slot = 1;
    while(slot < 4){
        randno = Math.floor(Math.random()*img_array.length);
        document.getElementById("slot"+slot).innerHTML = '<img src="'+img_array[randno]+'.png"/>';
        slot++;
        }
    requestAnimFrame(roll(start_time));     
    } else {
    document.getElementById("start").innerHTML = 'Roll The Slots Again?';
    document.getElementById("start").onclick = function(){start(); };
    }
    return false;
}

function start(){
start_time = new Date().getTime() / 1000;
document.getElementById("start").innerHTML = 'Processing......';
roll(start_time);
}

window.onload = function(){
document.getElementById("start").innerHTML = 'Roll The Slots';
document.getElementById("start").onclick = function(){start(); };
}

Where is my mistake ?

Answer 1

This just calls roll recursively for three seconds, which will exceed the maximum call stack size:

requestAnimFrame(roll(start_time));

You probably meant:

requestAnimFrame(function() {
    roll(start_time);
});