PHP - Invoking Anonymous Functions

Anonymous functions, also known as closures, are functions without a specific name. They are often used as callback functions or for creating inline functions. In PHP, you can define and invoke anonymous functions using the following syntax:

$anonymousFunction = function($param1, $param2) {
    // Function body
    return $param1 + $param2;
};
$result = $anonymousFunction(10, 20); // Invoking the anonymous function
echo $result; // Output: 30

Here's how to define and invoke anonymous functions in more detail:

Defining Anonymous Functions:

To define an anonymous function, use the function keyword without a function name, followed by the parameter list and the function body enclosed in curly braces.

$anonymousFunction = function($param1, $param2) {
    // Function body
    return $param1 + $param2;
};

Invoking Anonymous Functions:

Once you've defined an anonymous function, you can invoke it by using the variable name of the function followed by parentheses and arguments, just like you would with named functions.

$result = $anonymousFunction(10, 20); // Invoking the anonymous function

In this example, the anonymous function calculates the sum of two numbers, and invoking it with arguments 10 and 20 returns the result 30.

Anonymous functions are particularly useful when you need to create small, one-off functions, especially when working with functions that accept other functions as arguments, like in array manipulation functions, sorting functions, or event callbacks.