How can variable naming conventions affect the readability and functionality of PHP code?

Variable naming conventions can greatly affect the readability and functionality of PHP code. Using clear, descriptive names for variables can make the code easier to understand for other developers and for future reference. Consistent naming conventions also help maintain code consistency and reduce the likelihood of errors. By following a standard naming convention, such as using camelCase or snake_case, developers can improve the overall quality and maintainability of their PHP code.

// Bad variable naming convention
$var = 5;
$myVariable = "Hello";

// Good variable naming convention
$number = 5;
$greetingMessage = "Hello";