Question

I want to pass a function to another function. I think functions being passed like that are call delegates? I am having a hard time finding a good explanation for this kind of thing online. Is this the right way to do this?

function getCellContentByColumnIndex = function(row, index) {
    return $(row.children().get(index)).text();
}
function naturalSort(a, b, func) {
    //...
    var $a = func(a);
    var $b = func(b);
    //...
}

//usage  
naturalSort(x, y, getCellContentByColumnIndex);

Answer 1

Your code:

function getCellContentByColumnIndex = function(row, index) {
    return $(row.children().get(index)).text(); 
}

Is a syntax error. The following is a function declaration:

functon foo() {}

And this is a function expression:

var foo = function(){}

And this is a named function expression:

var foo = function bar(){}

There are a number of answers here on the differences, there is a detailed explanation in the article Named function expressions demystified which also covers many other aspects of function declarations and expressions.

The term “anonymous function” is jargon for a function expression that has no name and isn’t assigned to anything, e.g.

someFn( function(){...} )

where someFn is called and passed a function that has no name. It may be assigned a name in someFn, or not. Ic could just be referenced as arguments[0].

Passing a function is not delegating, that is jargon for the practice of putting a listener on a parent element and catching bubbling events, it is preferred in cases where it can replace say a click listener on every cell in a table with a single listener on the table.

Anyhow, passing a function is just like passing any other object:

function foo(){
  alert('foo');
}

function callIt(fn) {
  fn();
}

callIt(foo);  // 'foo'

In the above, foo is passed to callIt and assigned to the local variable fn, and is then called.