JS settimeout doesn't work?

Question

I've looked at similar questions but can't get setTimeout to work with a forEach loop, even using the index to increase the delay:

pointArray.forEach(function(p) {
    setTimeout(addPt(p, 24, red), pointArray.indexOf(p) * 100000);

});

See that I've increased the delay to a measurable amount of ms and have multiplied by the increasing index - I know the index works as I console log out and it increases up to 100 as that is the array length.

Regardless the console.log I have in addPt happens all at the same time. What is wrong here?

I'm voting to close this question as off-topic because you simply need to pass a reference and not the result of a function call. — Jonas Wilms, Dec 22 '17 at 22:27
`setTimeout(function(){addPt(p, 24, red);}, pointArray.indexOf(p)*100000);` — Alex Kudryashev, Dec 22 '17 at 22:28

Taplar · Accepted Answer · 2017-12-22T22:38:12.363

addPt(p, 24, red)

You are invoking the method immediately, instead of giving setTimeout a method reference. Such as

setTimeout(addPt, 3000);

However since you are providing inputs, there are a couple ways to do this with a method reference.

//a
setTimeout(function(){ addPt(p, 24, red); }, 3000);
//b
setTimeout(addPt.bind(addPt, p, 24, red), 3000);
//c as noted by Jonas W
setTimeout(addPt, 3000, p, 24, red);

Both will pass a method reference to setTimeout and let -it- execute the function after the duration passes.

JS settimeout doesn't work?

1 Answers1