Programmatically stop JavaScript execution in Firebug

Question

I am currently debugging complex JavaScript code with Firebug. I am looking for a way to stop the JavaScript execution as if it was a breakpoint programmatically.

Example:

instructions ...
degugger.breakpoint(); // the execution stops here as if a breakpoint was
                       // manually set
other instructions ...

Solution

You can use the debugger statement:

// your JS code
...
// break here
debugger;

It works in all major browsers.

Comments

[Kirtan]

It will also work with IE if you enable Script Debugging in the Internet Options.

[James Wiseman]

After you have done this, you should be then be able to use breakpoints in your IDE debugger. This saves you from having to declare multiple 'debugger;' lines of code across your application.

[snapfractalpop]

I'm surprised how long I've gone without realizing you could do this. Thanks, this is very helpful. I would add that, for Chromium on Linux, this line of code will only pause execution if the debugger is open (and the disable breakpoints toggle is not selected).

[JonnyRaa]

this didn't work for me in firefox. Do you have to have the debugger open? I had firebug open but was looking at the console + network tabs. I wasn't actually interested in the code/state at the time but just wanted the console output to stop

[James Dunn]

The debugger directive now works in Opera. (Tested in Opera 28)