Loop function to play random movieclip

Question

I'm using Adobe Animate to create a simple HTML5 Canvas animation that has stars animating randomly in the background. I have 10 stars named star1 - star10 as I want to only have 10 of them playing in specific places. I've been trying to create a function that will loop, pick a random number from 1-10 then play that movieclip.

This is my current code:

setInterval(function(){
    var myNum = Math.round(Math.random() * 10) + 1;
    thisMc = this["star" + myNum];
    thisMc.play();
}, 800);

The function is looping and is picking a random number between 1-10, but I just can't get it to play the movieclip. When I use this["star" + myNum]; it comes back as unidentified, but if I use ["star" + myNum]; then it comes back as ["star1"]. I'm not sure how to get the code to compile the actual movieclip name and to play it.

I thought that I needed to use 'this' for it to compile the movieclip name. In ActionScript I could use eval to compile the movieclip name. I've searched around a lot here and on Google and thought that using ["star" + myNum]; would work the same as eval used to. As far as code goes, this is all of it other than the 10 movieclips on the canvas which are named star1 - star10. — mortalbug, Nov 29 '18 at 11:57
If you `console.log(this)`, it will probably point to the anonymous function context. How are you having the movie clips in the canvas? Do they have an id attribute? — lloydaf, Nov 29 '18 at 12:03
I did console.log(thisMc); which came back with unidentified when I had thisMc = this["star" + myNum]; the console came back with ["star1"] or whatever random number it'd picked. Yes, the movieclips all have id attributes and I can get them to play if I just use this.star1.play(); (or whatever number) outside of the function. — mortalbug, Nov 29 '18 at 12:11
When I try to use console.log(this); I just get a list of hundreds of variables in the console window. — mortalbug, Nov 29 '18 at 12:14
Ok understood what you are saying. Try the window object. `thisMc = window["star"+myNum];` then, you can try `thisMc.play()`. Does that work? — lloydaf, Nov 29 '18 at 12:19
In the console it still comes back with unidentified' when I have console.log(thisMc); — mortalbug, Nov 29 '18 at 12:27

lloydaf · Accepted Answer · 2018-11-29T12:36:57.243

0

You have to save the context to another object outside the setInterval() function, and use that inside the function.

let ctx = this;
setInterval(function(){
    var myNum = Math.round(Math.random() * 10) + 1;
    thisMc = ctx["star" + myNum];
    thisMc.play();
}, 800);

This should work.

edited Nov 29 '18 at 12:36

answered Nov 29 '18 at 12:33

lloydaf

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Loop function to play random movieclip

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