Creating Reusable Code with PHP Functions

Functions are reusable blocks of code that perform specific tasks. They help to organize your code, improve readability, and promote code reusability.

Defining a Function

To create a function, use the function keyword followed by the function name and parentheses. The code to be executed goes inside curly braces.

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

Calling a Function

To use a function, you call it by its name followed by parentheses.

greet("Alice"); // Output: Hello, Alice!

Function Arguments

Functions can accept parameters (arguments) to pass data to them.

function addNumbers($num1, $num2) {
    $sum = $num1 + $num2;
    return $sum;
}

$result = addNumbers(5, 3);
echo $result; // Output: 8

Return Values

Functions can return values using the return keyword.

function calculateArea($length, $width) {
    $area = $length * $width;
    return $area;
}

$rectangle_area = calculateArea(4, 5);
echo $rectangle_area; // Output: 20

Function Scope

Variables declared within a function are local to that function and cannot be accessed outside it.

Built-in Functions

PHP provides a vast library of built-in functions for various tasks like string manipulation, array operations, mathematical calculations, and more.

$text = "Hello, world!";
$length = strlen($text); // Get string length
echo $length; // Output: 12

By effectively using functions, you can break down complex problems into smaller, manageable units. This improves code organization, maintainability, and efficiency. In the next article, we’ll explore PHP arrays.