> ## Documentation Index
> Fetch the complete documentation index at: https://docs.js-confuser.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Best Practices

**Avoid undeclared variables**

* JS-Confuser only renames variables you explicitly define, but undeclared variables can still cause issues.
* Always declare variables using `var`, `let`, or `const`.
* Avoid referencing global variables directly. Use `window.MyGlobalVar` instead of `MyGlobalVar`.

**Don't rely on `function.name`**

* [Rename Variables](../options/renameVariables) and related options will break this behavior. Most build tools recommend avoiding this pattern altogether.

**Don't use `eval()` to reference or modify local variables**

* See [Rename Variables](../options/renameVariables) for how to properly support this use case.

**If your code relies on `function.length`**

* Enable [Preserve Function Length](../options/preserveFunctionLength) to ensure `function.length` remains accurate.

**Avoid string-based placeholders**

* If your code uses string placeholders like `"COOKIE_NAME"`, replace them with identifiers such as `COOKIE_NAME`. Strings are heavily encoded by JS-Confuser and may not behave as expected.