What are the potential issues with mixing German and English variable names in PHP code, and how can they be avoided?

Mixing German and English variable names in PHP code can lead to confusion for developers who may not understand both languages. To avoid this issue, it's best to stick to one language for variable names throughout the codebase. If using English variable names is the standard practice, then all variables should be named in English to maintain consistency and readability.

// Incorrect: Mixing German and English variable names
$benutzerName = "John";
$userEmail = "john@example.com";

// Correct: Using consistent English variable names
$userName = "John";
$userEmail = "john@example.com";