PHP call function from another file with examples

To call a function from another file in PHP, you need to import the file where the function is defined before calling it.

You can import a PHP file by using the require statement.

For example, suppose you have a file named library.php with the following content:

// library.php

function greetings() {
    echo "Hello World!";
}

To call the greetings() function from another file, you need to import the library.php file as shown below:

// 👇 import the PHP file
require "library.php";

// 👇 call the function
greetings();

By using the require statement, PHP will evaluate the code in that file before running the current file.

The same method works when you have a function with parameters as well:

// library.php
<?php
function sum(int $x, int $y) {
    return $x + $y;
}

Just add the parameters when calling the function in another file as follows:

// index.php
<?php
require "library.php";

// 👇 call the function with parameters
$n = sum(10, 9);

echo $n; // 19

Now you’ve learned how to call a function from another file in PHP. Nice work! 👍