IE9 Javascript Error :: Undefined/Null-Collection of common programming errors

I have a piece of JS (below) that in IE9 is giving me the following error:
The value of the property ‘$’ is null or undefined, not a Function object

In FFX, Chrome, and Safari I get no issues. Not sure whats going on here – still learning a bit, so be easy on me if it’s obvious 🙂

Thanks in advance!

 
    
    
    
        function LA_triggerOverlay() {
            $("#la-w-001-overlay").toggle();
        };
       $(function () {
           $("#sample-widget").show();
       });
   
   
       
   

1. In latest versions of chrome and FF [and maybe Safari as well] ‘$’ is natively supported as a synonym for document.getElementById()

   IE 9 does not support this natively, hence you get the error you stated.

   However, as gentleman above points out, you maybe missing a library [most likely jQuery]. I would highly suggest to include jQuery in your page and try the code again.

   You can reference jQuery easily via this snippet:

   So if this is the missing piece, it should solve your problem.

2. Presumably you haven’t included a script above that code that defines the $ symbol (e.g., jQuery or similar). There is no default $ symbol, it’s just a symbol that’s used by a couple of popular libraries (jQuery, Prototype, and MooTools primarily). Unless you include one of those with a script tag above your code, you’ll get this error — in any browser.

Originally posted 2013-11-09 19:26:14.