How important is documentation and clear concepts in PHP programming, especially for long-term code maintenance and understanding?

Documentation and clear concepts are crucial in PHP programming for long-term code maintenance and understanding. Proper documentation helps developers understand the codebase, its functionality, and how different components interact with each other. Clear concepts ensure that the code is structured logically and efficiently, making it easier to maintain and update in the future.

/**
 * This function calculates the sum of two numbers.
 * 
 * @param int $num1 The first number
 * @param int $num2 The second number
 * @return int The sum of the two numbers
 */
function calculateSum($num1, $num2) {
    return $num1 + $num2;
}