Callback

A callback is a function passed as an argument to another function.

Callbacks allow functions to execute custom logic.

They are commonly used with array functions and event handlers.

Example Callback

function greet($name) {
    echo "Hello $name";
}

function processUser($callback) {
    $callback("John");
}

processUser("greet");

Using an Anonymous Function as Callback

processUser(function ($name) {
    echo "Welcome $name";
});

Callback with Array Functions

$numbers = [1,2,3,4];

$result = array_map(function ($n) {
    return $n * 2;
}, $numbers);

print_r($result);