How can PHP functions be organized and structured to improve readability and maintainability?

To improve readability and maintainability of PHP functions, it is important to organize them logically and structure them consistently. One way to achieve this is by grouping related functions together in separate files or classes. Additionally, using meaningful function names, comments, and proper indentation can also enhance code readability.

// Example of organizing PHP functions in separate files

// functions.php
function calculateSum($a, $b) {
    return $a + $b;
}

// utils.php
function validateEmail($email) {
    return filter_var($email, FILTER_VALIDATE_EMAIL);
}