Are there any best practices for handling variables and arrays in PHP?

When handling variables and arrays in PHP, it is important to follow best practices to ensure code readability, maintainability, and efficiency. One common best practice is to use meaningful variable names that describe the data they hold. Additionally, it is recommended to properly initialize variables and validate array keys before accessing them to avoid errors.

// Example of using meaningful variable names and initializing variables

// Bad practice
$a = 10;
$b = 20;
$c = $a + $b;

// Good practice
$firstNumber = 10;
$secondNumber = 20;
$sum = $firstNumber + $secondNumber;