Creating multiple dynamic instances via new.lib HTML5 Canvas

[Andrius5CCD]

I am rebuilding my old game built with AS2 for Adobe Animate canvas. Got stuck while duplicating the objects. Found this thread from JoãoCésar using new lib, and everything is fine but I would like to create multiple instances form my library item 'bug' (has linkage 'bug' as well). Pardon my code, but I would like to be something like this:

var that = this;
this.buttonAdd.addEventListener("click", addFromLibrary);

function addFromLibrary(e) {
	for (var i = 0; i < 5; i++) {
		var ["bug" + i] = new lib.bug();
		["bug" + i].x = 10 * i;
		["bug" + i].y = 10 * i;
		that.addChild["bug" + i];
	}
}

... where I expect all 5 flying bugs on stage. Obviously it doesn't work with dynamic variables. As I understand bracket notation should be used over eval in Animate javascript, but not sure how exactly should I use it. As furhter more I would like to access these created bugs for collision event as well. Many thanks!

[JoãoCésar · Accepted solution]

Hi.

There's no need to use bracket notation in this situation. But if you really need to use it, you should write something like:

that["bug" + i].x = 10 * i;

Because bracket notation is used to access properties of an object.

And for your code to work, you could do something like this:

var that = this;

function addFromLibrary(e)
{
	var i, bug;
	
	for (i = 0; i < 5; i++)
	{
		bug = new lib.bug();
		bug.x = 10 * i;
		bug.y = 10 * i;
		that.addChild(bug);
		that.bugs.push(bug);
	}
}

that.bugs = [];
that.buttonAdd.addEventListener("click", addFromLibrary);

Please notice that I'm storing the instances in a array for later reference. But it's not mandatory if all that you need is to spawn some instances at runtime.

I hope this helps.

Regards,

JC

[Andrius5CCD]

Thank you João,

Your suggestion worked as intended. Thanks a lot 🙂 I will try to develop the rest and hope to continue to move on. I believe I will make use of this array with instances as well. Have a great New Year!

Andrius

[JoãoCésar]

That's great, Andrius! You're welcome!

I wish you a happy New Year and a fun time developing your game!