Question

I remember coming across the solution for this problem.. There is a special term for this type of argument if I am not wrong.. But I just can’t remember exactly what it is. I try searching for it on the web but to no avail.. So here it comes:

I want to pass an argument that consists of a function. What should I do?

function meow(cat){
    var z = $("#nyan").position().cat;
    alert(z);
}

meow(left);

or

function meow(cat){
    var z = $("#nyan").cat();
    alert(z);
}

meow(height);

Answer 1

That’s not quite a function; it looks more like you want a name of a property.

I’m just going to throw a few suggestions at you and see which one you like the most.

function meow(cat) {
    var z = $("#nyan").position()[cat];
    alert(z);
}

meow("left");

… or …

function meow(cat) {
    var z = $("#nyan")[cat]();
    alert(z);
}

meow("height");

… or, really using a function:

function meow(getter) {
    var z = getter($("#nyan"));
    alert(z);
}

meow(function(nyan) { return nyan.position().left });
meow(function(nyan) { return nyan.position().top });
// etc.

Edit: the most important thing is that a.b is equivalent to a["b"]—note the quotes in the latter.

So if you want a.x if width is true or a.y if width is false, for example:

var result = a[width ? "x" : "y"];