Does a tool exist for dynamically altering running javascript in a browser? [closed]

Question

Does a tool exist for dynamically altering running javascript in a browser? For example, to change the values of javascript variables during runtime.

Answer 1

So, Firebug really is one of the best options - or, if you are a developer that owns Visual Studio and want to debug using IE, you can do that. Let's assume you will do this with Firebug using Firefox.

First, determine where you want to alter the code and place the following line just before the line you want to start messing with:

debugger;

That will cause Firebug to stop the execution of the script at that point, at which point you can then step through the code and alter the values of variables.

You can also use Firebug to place breakpoints in by clicking to the left of a line of code in the script window of Firebug:

Answer 2

Firebug , or Venkman Javascript Debugger .