Using Function.toString to Troubleshoot JavaScript Issues

By  on  

Sometimes JavaScript bugs can be the most frustrating damn things in the world. That problem is compounded when a JavaScript file is created from multiple files on the server side or you simply aren't familiar with some of the code used in a project (i.e. troubleshooting an issue with a JavaScript framework you aren't familiar with. Sometimes just identifying the code within a function is enough to point you in the correct direction. So to quickly check the code for a given function, I'll type into the console something like:

myProblemFunction.toString();

That would return something like:

function myProblemFunction() {
	/* bunch of code here */
	
	some.problem().code;
	
	/* bunch of code here */
}

Awesome. Now that I can get the function code at a glance, I can more easily browse through what could be causing the issue and see what needs to be changed. Usually any hint you can get toward finding where the issue resides is a big help!

Recent Features

  • By
    CSS Filters

    CSS filter support recently landed within WebKit nightlies. CSS filters provide a method for modifying the rendering of a basic DOM element, image, or video. CSS filters allow for blurring, warping, and modifying the color intensity of elements. Let's have...

  • By
    7 Essential JavaScript Functions

    I remember the early days of JavaScript where you needed a simple function for just about everything because the browser vendors implemented features differently, and not just edge features, basic features, like addEventListener and attachEvent.  Times have changed but there are still a few functions each developer should...

Incredible Demos

  • By
    Fixing sIFR Printing with CSS and MooTools

    While I'm not a huge sIFR advocate I can understand its allure. A customer recently asked us to implement sIFR on their website but I ran into a problem: the sIFR headings wouldn't print because they were Flash objects. Here's how to fix...

  • By
    Create a Trailing Mouse Cursor Effect Using MooTools

    Remember the old days of DHTML and effects that were an achievement to create but had absolutely no value? Well, a trailing mouse cursor script is sorta like that. And I'm sorta the type of guy that creates effects just because I can.

Discussion

    Wrap your code in <pre class="{language}"></pre> tags, link to a GitHub gist, JSFiddle fiddle, or CodePen pen to embed!