Question

for example, say I use a factory to create a group of objects:

function factory() {
    e.x = 0;
    e.y = 0;
    return e;
}

How do I pass these objects into a render function?

For example:

function render() {
    a[0].someMethod;
}

function init() {
    for(i=0;i<10;i++) {
        things[i] = factory();
    }
    setInterval(render(things),40);
}

Answer 1

You need to use closure there:

setInterval(function(){
   render(things);
},40);

setInterval accepts callback function (function with name without ()) but when you do:

setInterval(render(things), 40);

You are actually calling the function (because of (things) parenthesis) right there inside setInterval which is wrong.