Passing a function into another function

Question

I have a function that is similar to this:

function foo(array1, fun) {
    var n;
    n = a.length;
    var i;
    for (i=0; i<=n; i++) {
        fun(a[i]);
    }
}

Now I want to create a function called mult(x) that I will pass into foo when I call it. My question is what do I put in the parameters of my mult function when I want to call:

foo(some_array, mult(x));

Answer 1

Just pass in a reference to it (its name only)...

foo(some_array, mult);

Alternatively, pass in an anonymous function...

foo(some_array, function() { ... });

The first argument of this function you pass in with will be set to a[i] like in the body on your function.