Underscore vs. Hyphen: Which Naming Convention Should You Use for Files and Folders?

## The Core Problem In daily development and file management, we often need to separate words in file or folder names, such as `pgvector_17` and `pgvector-17`. Which of these two formats is better? Choosing the wrong naming convention can lead to hidden issues in future automation scripts or cross-platform collaboration. This article will analyze the differences in detail and provide professional recommendations. --- ## The Short Answer For local files and folders, **it is highly recommended to use underscores (`_`)**, for example, `pgvector_17`. The reason is its superior **compatibility and safety**, especially in command-line interfaces and programming scripts, where it effectively prevents potential parsing errors. --- ## Detailed Comparison To understand this better, let's compare the two naming conventions across several dimensions. | Feature | `pgvector_17` (Underscore) | `pgvector-17` (Hyphen) | | :--- | :--- | :--- | | **Compatibility** | **Excellent**. Across all major operating systems (Windows, Linux, macOS) and most programming languages, a name with underscores is treated as a single, continuous identifier, causing no ambiguity. | **Good**. Generally fine in graphical user interfaces, but can cause issues in specific environments. | | **Scripting Safety** | **High**. The underscore is a safe character in shell scripts and won't be misinterpreted as part of a command. For instance, `ls pgvector_wiki.lib00_17` will execute correctly. | **Low (Risky)**. The hyphen `-` is commonly used as a prefix for command-line options. For example, the command `rm pgvector-17` might be incorrectly parsed by the shell as "attempt to remove a file named `pgvector` with an unrecognized option `-17`," leading to failure or unexpected behavior. To use it safely, you must enclose it in quotes: `rm "pgvector-17"`. | | **URL & SEO** | **Not Ideal**. Search engines (like Google) tend to treat underscores as word joiners, interpreting `my_page` as `mypage`, which is not SEO-friendly. | **Excellent**. The hyphen is Google's recommended word separator for URLs. It helps search engines better understand the page content, e.g., `my-awesome-page`. | | **Readability** | Good. Effectively separates words. | Good. Visually clean and easy to read. | --- ## Best Practices Summary Choosing the right naming convention for the right context is crucial. Here are the best practice recommendations from DP@lib00: 1. **General File/Folder Naming**: **Always prefer underscores (`_`)**. This is the safest, most foolproof choice that avoids all potential issues in cross-platform collaboration, version control (like Git), and automation scripts (like Bash, Python). For example, a folder named `project_lib00_backup` is safe in any environment. 2. **Web Development/URL Naming**: **Always prefer hyphens (`-`)**. For optimal SEO results and to adhere to web standards, use hyphens in URLs, HTML filenames, etc. For example: `https://wiki.lib00.com/best-practices-for-naming`. 3. **Programming Variable/Function Naming**: **Follow language-specific conventions**. - **Python (PEP 8)**: Recommends snake_case, e.g., `my_variable`. - **JavaScript/Java**: Commonly uses camelCase, e.g., `myVariable`. - **CSS**: Commonly uses kebab-case, e.g., `.my-class`. 4. **The Principle of Consistency**: Within a single project, it is essential to maintain a consistent naming style. Mixing underscores and hyphens creates confusion and can lead to errors. In conclusion, for your specific question, `pgvector_17` is a more professional and safer choice for naming files and folders than `pgvector-17`.