vscode cannot add breakpoint

Question: Why does breakpoints in VS Code not work? Answer: The reasons for breakpoint failure include running environment problems (direct code running), code problems (synchronization error), configuration problems (launch.json error), source code mapping problems (inaccurate code mapping after compilation).

VS Code breakpoint failed? Don’t panic, let’s talk!

You scratched your head at VS Code and found that the breakpoint looked like a naughty elf, and you couldn't stop it? I understand this feeling! In this article, we will analyze the failure of VS Code breakpoints, help you quickly solve the problem and deeply understand the mechanism behind it. After reading it, you can not only fix the problem, but also improve debugging skills and become a debugging expert.

Basic review: Debugger and running environment

VS Code's powerful debugging function relies on its good communication with your code running environment. This is not a simple "I write the code, you run it", which involves the interaction between the debugger and the running environment (such as Python interpreter, Node.js, etc.). Whether the breakpoint setting is successful depends largely on whether they are "come-friendly". The debugger is responsible for listening to code execution and pausing at breakpoints; the running environment is responsible for actually executing your code. Any obstacle to information transmission between the two will cause breakpoint failure.

Core question: Why don't breakpoints work?

There are many reasons for breakpoint failure, but ultimately, they are related to the connection, configuration, and code itself of the debugger and the operating environment.

• Running environment problem: You may have run the code directly, rather than starting it through the debugger of VS Code. VS Code's debugger needs to be attached to your program at startup to listen for breakpoints. It's like you try to command a person remotely on the phone, but you don't make the phone call at all.
• Code problem: Your code may have syntax errors, or breakpoints are set in code segments that cannot be executed (such as inside a dead loop, or branches where if conditions are never valid). It's like you direct someone else to a place that doesn't exist.
• Configuration issues: VS Code's launch.json file is responsible for configuring the debugger. If the configuration is wrong, the debugger will not be able to connect to your program correctly. It's like you're commanding someone with a wrong map.
• Source Maps: If you use compiled languages ​​(such as TypeScript, Sass), there may be mapping problems between the compiled code and the source code, resulting in breakpoints not being able to accurately correspond to the source code lines. It's like you use translation software to direct others, but the translation is wrong.

Hands-on practice: Solve breakpoint failures

Let's take a few examples to see how to solve these problems.

Example 1: Run the code directly

You may be used to running Python scripts directly in the terminal, such as python my_script.py . Running this way, the debugger of VS Code cannot intervene. The correct way to do this is to use the debugging function to start the script in VS Code. In VS Code, click the Debug Panel (usually a bug icon), then select your Python environment, and then click the Run button.

Example 2: Syntax error

A simple syntax error can prevent your code from executing to a breakpoint. Double-check your code to see if there are any syntax errors. VS Code usually marks errors with wavy lines.

Example 3: launch.json configuration

The launch.json file is located in the .vscode folder. Make sure program attribute points to your code file and type attribute points to the correct debugger (such as python ). A typical launch.json configuration is as follows:

 <code class="json">{ "version": "0.2.0", "configurations": [ { "name": "Python: Current File", "type": "python", "request": "launch", "module": "my_module", // 或者"program": "my_script.py" "console": "integratedTerminal" } ] }</code>

Example 4: Source Code Mapping

If you use TypeScript, make sure your tsconfig.json is configured correctly and VS Code can correctly map compiled JavaScript code to your TypeScript source code.

Performance optimization and best practices

The key to efficient debugging is to streamline the code, set reasonable breakpoints, and make good use of the debugger functions, such as single-step execution, variable viewing, etc. Avoid setting too many breakpoints, which will reduce debugging efficiency. Developing a good code style and writing clear and easy-to-understand code can also make debugging much easier.

Remember, debugging is a process of iterating repeatedly. If you try more and summarize more, you can become a VS Code debugging expert! Don't forget to check your running environment, code, configuration, and source code mapping. I wish you a smooth debugging!

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