JavaScript Debugging


JavaScript debugging is the process of identifying and fixing errors or bugs in JavaScript code. Debugging is an essential skill for any developer, as it can save a lot of time and frustration in the development process.

It is common to have errors while writing codes and the errors can be due to syntax or logical. These errors create a lot of ambiguity in the logic and understanding of both users and programmers. There can also be errors in the code which can remain invisible to the programmer’s eye and can create havoc.

To identify these errors we need Debuggers that can go through the entire code or program, identify the errors and also fix them.


1. debugger

The debugger keyword is used in the code to force stop the execution of the code at a breaking point and calls the debugging function. The debugger function is executed if any debugging is needed at all else no action is performed. Let’s see JavaScript program on debugging:

Debugging is difficult. But fortunately, every current browser includes a JavaScript debugger. Errors should be notified to the user by default as built-in debuggers can be turned on and off. A debugger also allows you to set breakpoints (points at which code execution can be stopped) and watch variables while the code is running.

Most modern browsers come with built-in debugging tools that allow you to step through your code line by line and inspect variables and expressions. This can be a powerful tool for identifying and fixing bugs.

Example

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2. Use of console.log() method

One of the most effective ways to debug JavaScript code is to use console.log() statements to print out values at different points in your code. This can help you identify where the code is breaking or where unexpected values are being returned.

Example

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3. Setting Break Points

The console.log() is a good way to debug errors but setting breakpoint is a faster, efficient and better method. In this method, Breakpoints are set in code which stops the execution of code at that point so that the values of variables can be examined at that time.

Here are some advantages of using Breakpoints over console.log() method:

  • In console.log() method the user has to understand the code and manually put console.log() at points in the code. But in the breakpoints method, we can set breakpoints through Developers tool anywhere in code without even knowing it.
  • In console.log() method we have to manually print values of different variables but at a certain breakpoint, all the values of all variables are displayed automatically in the Developers tool.