[removed] Extend a Function

Question

The main reason why I want it is that I want to extend my initialize function.

Something like this:

// main.js

window.onload = init();
function init         


        

Answer 1

2017+ solution

The idea of function extensions comes from functional paradigm, which is natively supported since ES6:

function init(){
    doSomething();
}

// extend.js

init = (f => u => { f(u)
    doSomethingHereToo();
})(init);

init();

As per @TJCrowder's concern about stack dump, the browsers handle the situation much better today. If you save this code into test.html and run it, you get

test.html:3 Uncaught ReferenceError: doSomething is not defined
    at init (test.html:3)
    at test.html:8
    at test.html:12

Line 12: the init call, Line 8: the init extension, Line 3: the undefined doSomething() call.

Note: Much respect to veteran T.J. Crowder, who kindly answered my question many years ago, when I was a newbie. After the years, I still remember the respectfull attitude and I try to follow the good example.