How does .apply(Math, arrayName) work? (javascript)

Question

There is more than one stackoverflow question about how to find the min or max of an array of values in javascript. This is not that question.

I want to know why pas

Answer 1

What apply does with its first argument, is simply setting the context (this) for the function that it is called on.

So lets say, you have an object like this:

var obj = {
    a: 1,
    b: function () {
        return this.a;
    },
    c: function () {
        return 3;
    }
}

If you call obj.b(), you will get 1 as returned value, since this in this scenario is defined by calling b with obj in front of it (this === obj). To change that, you can use apply:

obj.b.apply({a:2});

This will return 2, because you are now explicitly settings this to {a:2}.

BUT: if you have a function, that doesn't make use of this internally, than it doesn't matter what value this has. So you can call:

obj.c();

or one of these:

obj.apply.c(null);
obj.apply.c(undefined);
obj.apply.c("xyz");

But you will always get the same result 3. It is like setting a variable that you never use. No matter what value it is, it doesn't affect the outcome.

So apparently Math.min doesn't use this and therefore doesn`t break when passing an "invalid" context.