Self invoking functions javascript

Question

I wrote a self invoking function in both firefox and chrome it it wouldn't invoke.

I wrote something to the effect of

(function () { alert("THE"); })();

do self invoking functions not work in current browsers?

I did include all essential tags and all other code works on the page

Springing

"self invoking"? what do you mean? btw, it does work on chrome – Carboloy

Do you have a link to the page? That code works. What if you replace it with alert("THE"); without the function. Does the alert execute? I don't think so. – Monometallic

this part of the code works perfecly. Show any surrounding code. Make sure there is no other JavaScript that produces an error (you can check Firebug's or Chrome's console) – Rugging

Answer 1

"Self-invoking functions" are not really a part of javascript, it's just a term that people are calling a specific pattern of code (like AJAX, etc.); these patterns should work anywhere that javascript works.

What you're calling a "self-invoking function" is just creating an anonymous function and immediately calling it (as opposed to say storing it in a var, as an object value, as a function param, etc.).

That is, the following are basically the same:

var f = function(){...}; f()

and

( function(){...} )()

So because your 'self-invoking function' is a basic part of javascript, there is no possible way it's not working unless the insides aren't working or your environment is messed up. You could copy-paste your code onto a new blank page, and it would work fine. Something else must be going wrong:

Check your errors in your dev console. Specifically, check to make sure you don't have a syntax error or that there isn't some weird thing going on with the webpage you're testing it on (e.g. if you somehow redefine alert...).

Devest

You're right the problem was I had a syntax error, the statement before it had an implicit semi-colon, which should have been explicit. It caused a parsing error – Springing

Answer 2

I had this issue with a self invoking function which produced this error...

Uncaught TypeError: object is not a function

The problem was caused by not having a semi colon ending the line before the opening bracket

Wormy

Yeah I had the same error, added the semicolon and voila. – Recuperate

Answer 3

<script type="text/javascript">
  (function() {
     alert('Hello World!');
  })();
</script>

Works in every browser I have installed on this machine.

Asmara

Answer 4

That function works. Javascript supports functional programming, so for a browser not to run that code, even for a very old browser that would be absurd. Are you sure that statement is being reached? Try debugging javascript that occurs before that statement.

Monometallic

Answer 5

This function definitely works. I would check your browser's console for any js errors in your page. Perhaps you could try to put a simple console.log function at the beginning of your script to see if any JavaScript is being called in the first place.

Rizas

Answer 6

This self invoking function with return value will work in all current browsers(Safari, Chrome and Firefox) without issue. This function executes immediately, automatically and anonymously.

<script type="text/javascript">
    alert((function(){
        return("Hello World");
    })());
</script>

Sanhedrin

Answer 7

I had a similar problem. I'm mentioning it below.

I couldn't run this self-invoking function on any browser

(function myfunc() {
    var x = 34;
    console.log(x);
})();

but whenever I added window.onload like below, it worked fine:

window.onload = (function myfunc() {
    var x = 34;
    console.log(x);
})();

Prewar