PHPIntermediate

PHP Functions

Define functions in PHP: parameters and return values, default arguments, arrow functions, and recursion with examples.

01Define a function

main.php

<?php
function greet($name) {
    return "Hello, $name!";
}
echo greet("World"), "\n";

Output

Hello, World!

main.php

<?php
function power($base, $exp = 2) {
    return $base ** $exp;
}
echo power(5), "\n";
echo power(2, 10), "\n";

Output

25
1024

main.php

<?php
$square = fn($x) => $x * $x;
echo $square(6), "\n";

Output

main.php

<?php
function factorial($n) {
    if ($n <= 1) return 1;
    return $n * factorial($n - 1);
}
echo factorial(5), "\n";

Output