Question

In terms of performance and the data structure created, is:

function coords(xpos, ypos, zpos){
    this.xpos = xpos;
    this.ypos = ypos;
    this.zpos = zpos;
    return this;
}
var coordinates = coords(0, 0, 0); // notice I am not calling new

The same as:

function coords(xpos, ypos, zpos){
    return {
        xpos : xpos,
        ypos : ypos,
        zpos : zpos, 
    };
}
var coordinates = coords(0, 0, 0);

Is there are more performant way of generating the coordinates assuming I have a lot of them.

Answer 1

In the first approach for creating an object you have to use

var coordinates = new coords(0, 0, 0); and in javascript using new is expensive. In the second approach executing the function will return you a coordinate object.

I prefer the second approach though it doesn’t make much difference in modern browsers.

here is a simple benchmark http://jsperf.com/objecr-vs-fn-perf-test

in Firefox 7 the first approach is ~75% slower than second and in chrome 17 it si ~30% slower