How do I use Clang format to indent with four spaces?

To use Clang-format to indent your code with four spaces, you need to configure its settings. Clang-format uses a configuration file, typically named .clang-format, placed in your project's root directory (or any parent directory). Here's how to achieve four-space indentation:

1. Create or Modify the `.clang-format` File:

- If you don't already have one, create a file named .clang-format in your project's root directory.

- If you have an existing .clang-format file, locate the setting related to indentation.

2. Set the `IndentWidth` Property:

- Inside the .clang-format file, you will need to set the IndentWidth property to 4. Below is an example of the .clang-format file content:

---
Language: Cpp
BasedOnStyle: LLVM
IndentWidth: 4
UseTab: Never
...


- In this example, Language: Cpp specifies this config is for C++ files, if you have other language use `Language: JavaScript` for example, BasedOnStyle: LLVM sets a base style which is good to keep, UseTab: Never, ensures that it uses spaces instead of tabs. The important line here is IndentWidth: 4, which dictates the use of four spaces for indentation.

3. Apply Clang-format:

- After saving your .clang-format file, run clang-format on your code.

- If you are using a CLI, you could run:

clang-format -i your_file.cpp

- or for multiple files:

clang-format -i .cpp

- The -i flag means to do it in-place (modify the original file), otherwise you can pass an output file name using the -o flag.

- In some code editors, it is possible to bind the format action to a hotkey or to perform auto-formatting on file save. For example, you can do this in VS Code, with Clang-format extension

4. Verify the Indentation:

- After formatting, your code will be indented with four spaces at each indentation level. If it still doesn't work, verify that the file extension matches the Language entry in your config.

Complete .clang-format Example for C++:

---
Language: Cpp
BasedOnStyle: LLVM
IndentWidth: 4
UseTab: Never
ColumnLimit: 80
...


Other Considerations:

- Clang-format is highly configurable. In addition to setting the indent width, other formatting options can be set here. You can also define a style based on other styles, such as Google, Chromium, etc.

By using these settings, you can configure Clang-format to consistently indent your code with four spaces, ensuring a clean and readable codebase.

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