How can the use of closures simplify refactoring and improve code readability in PHP development?

Using closures in PHP can simplify refactoring by encapsulating logic into a single function that can be easily reused and passed around. This can improve code readability by making it clear where certain functionality is defined and how it is being used throughout the codebase. Closures also allow for more flexible and dynamic code structures, making it easier to make changes and modifications without affecting other parts of the code.

// Before using closures
function add($a, $b) {
    return $a + $b;
}

function multiply($a, $b) {
    return $a * $b;
}

// After using closures
$calculate = function($operation, $a, $b) {
    return $operation($a, $b);
};

$result1 = $calculate(function($a, $b) {
    return $a + $b;
}, 5, 3);

$result2 = $calculate(function($a, $b) {
    return $a * $b;
}, 5, 3);

echo $result1; // Output: 8
echo $result2; // Output: 15