What are the potential performance implications of using separate functions versus if() statements in PHP code?

Using separate functions can lead to better code organization, readability, and reusability compared to using if() statements. However, using separate functions may introduce a slight performance overhead due to the function call overhead. In most cases, the performance difference is negligible, but if performance is a critical concern, using if() statements may be more efficient.

// Using separate functions for better code organization
function processInput($input) {
    // process input here
}

function validateInput($input) {
    // validate input here
}

$input = $_POST['input'];

if(validateInput($input)) {
    processInput($input);
}