How to change the value of js local variable when debug in Chrome console

Question

When I debug javascript with the Chrome console, I want to change a local variable of a function. I know how to change the value of global variables, but how do I change the value of a local variable when debugging in the Chrome console?

Answer 1

You don't debug in the Chrome console. You do debug in the Chrome debugger. And if you are stopped at a breakpoint in the debugger, you can use the console to change the value of any in-scope variable by assigning to it.

For instance, open dev tools and run this code, reading the comments:

 function foo() { var bar = 42; // Normally, you don't have to use a hardcoded breakpoint like // the one that follows, you can set a breakpoint from within the // debugger just by navigating to the line of code and clicking in // the left-hand gutter. But in Stack Snippets the easiest way to // do one is to use the debugger statement: debugger; // Now, when stopped on the breakpoint, type this in the console: // bar = 67; // ...and press Enter. // Then hit the arrow button to allow the script to continue console.log(bar); // ...and this will log 67 instead of 42. } foo(); 

Answer 2

Try setting a break point where you would want to redefine the local variable's value to a different one. Then you get access to all the data in that scope.

This might help