PHP Functions

Functions in PHP are blocks of reusable code that perform a specific task. They help make your code modular, reusable, and easier to debug. In this tutorial, we’ll explore how to create and use functions in PHP.

Creating a Function

To define a function in PHP, use the function keyword followed by the function name and parentheses:

<?php
    function sayHello() {
        echo "Hello, World!";
    }
    ?>

Calling a Function

To execute the code inside a function, simply call it by its name followed by parentheses:

<?php
    sayHello(); // Output: Hello, World!
    ?>

Functions with Parameters

You can pass data into a function using parameters:

<?php
    function greet($name) {
        echo "Hello, $name!";
    }
    greet("Alice"); // Output: Hello, Alice!
    ?>

Functions with Return Values

Functions can return a value using the return statement:

<?php
    function add($a, $b) {
        return $a + $b;
    }
    $result = add(5, 3);
    echo "The result is: $result"; // Output: The result is: 8
    ?>

Default Parameter Values

You can specify default values for parameters, which are used if no value is provided when the function is called:

<?php
    function greet($name = "Guest") {
        echo "Hello, $name!";
    }
    greet(); // Output: Hello, Guest!
    greet("Alice"); // Output: Hello, Alice!
    ?>

Using Variable-Length Arguments

PHP allows you to create functions that accept a variable number of arguments using ... (splat operator):

<?php
    function sum(...$numbers) {
        return array_sum($numbers);
    }
    echo sum(1, 2, 3, 4); // Output: 10
    ?>

Anonymous Functions

PHP supports anonymous functions (also known as closures), which are functions without a name:

<?php
    $greet = function($name) {
        echo "Hello, $name!";
    };
    $greet("Alice"); // Output: Hello, Alice!
    ?>

Next Steps

Practice creating your own functions with different parameters and return types. Functions are a powerful tool for organizing and reusing code in PHP applications.