How to Start Debugging in VS Code

Debugging is a crucial part of the software development process, and Visual Studio Code (VS Code) offers a powerful built-in debugger to make this task easier. This article provides a quick, step-by-step guide on how to configure and start a debugging session in VS Code, covering the basic setup, creating a launch configuration, and using the debug controls for various programming languages.

Step 1: Open Your Project and Set a Breakpoint

Before starting a debug session, open the folder containing your source code in VS Code. To observe how your code behaves during execution, you should set a breakpoint.

  1. Open the source code file you want to debug.
  2. Hover your mouse to the left of the line numbers.
  3. Click to place a red dot (breakpoint). The execution of the program will pause at this line.

Step 2: Open the Run and Debug View

To access the debugging features, navigate to the Run and Debug view:

Step 3: Start the Debugging Session

Depending on your project type, you can start debugging using one of two methods:

Method A: Quick Start (Run and Debug)

If you have a simple single-file project (such as a Python, JavaScript, or Go file), you can start debugging immediately: 1. Click the Run and Debug button in the Run and Debug view. 2. Select your environment/language from the dropdown list if prompted. 3. VS Code will automatically run the active file and pause at your breakpoint.

Method B: Configure a launch.json File

For complex projects, web applications, or specific runtime environments, you will need to create a configuration file: 1. In the Run and Debug view, click on create a launch.json file. 2. Select your workspace environment (e.g., Node.js, Python, C++). 3. VS Code will create a .vscode folder containing a launch.json file. 4. Customize the configurations (such as arguments, environment variables, or program paths) within this JSON file. 5. Save the file, select your configuration from the dropdown menu at the top of the Run and Debug view, and click the green Play (Start Debugging) button or press F5.

Step 4: Use the Debug Toolbar

Once the session starts, the Debug Toolbar will appear at the top of the screen. You can use these controls to navigate your code: