Learn Defining and Calling Functions | Getting Started with PHP Functions

How to Define a Function

To define a function in PHP, use the function keyword, followed by the function name and a pair of parentheses. The code you want the function to run goes inside curly braces. Here’s the basic structure:

function functionName() {
    // Code to run when the function is called
}

Example:

function sayHello() {
    echo "Hello, world!";
}

This defines a function named sayHello that prints "Hello, world!" when it is called.

How to Call a Function

To use your function, write its name followed by parentheses:

sayHello();

This line runs the code inside the sayHello function, so you will see Hello, world! printed on the screen.

Key Points

Always start a function definition with the function keyword;
Function names should be descriptive and use only letters, numbers, and underscores;
Don't forget the parentheses, even if your function does not take any input;
Call a function by writing its name followed by parentheses.

By defining and calling functions, you can make your PHP programs more organized and efficient.

functions_example.php


              123456789101112131415
            
<?php
// Define a function named 'addNumbers' that takes two arguments
function addNumbers($a, $b) {
    // Calculate the sum of the two arguments
    $sum = $a + $b;
    // Return the result to the caller
    return $sum;
}

// Call the 'addNumbers' function with 5 and 7 as arguments
$result = addNumbers(5, 7);

// Print the returned value to the screen
echo "The sum of 5 and 7 is: " . $result;

Everything was clear?

Thanks for your feedback!

Section 1. Chapter 2

Ask AI

Ask anything or try one of the suggested questions to begin our chat

Suggested prompts:

Can you show me how to add parameters to a PHP function?

What happens if I call a function before it is defined in PHP?

Can you explain how to return a value from a PHP function?

Swipe to show menu