PHP for the Web·PHP from first script to a working app

Functions and scope

Type your parameters and returns, use defaults and understand what a function can see.

Beginner 14 min read Lesson 3 of 300 Challenge included

What you will be able to do

Type parameters and return values.
Use default values for optional arguments.
Return early instead of nesting.
Arrow functions capture outer variables automatically.

In plain English

A function is a named, reusable transformation. In PHP, variables outside the function are not automatically visible inside it. Pass data in as parameters and return data out rather than reaching for globals.

functions.phpPHP

<?php
declare(strict_types=1);

function formatMinutes(int $minutes, string $suffix = 'min'): string
{
    return $minutes . ' ' . $suffix;
}

$double = fn (int $n): int => $n * 2;

echo formatMinutes(12);
echo "\n" . $double(7);

Your turn

Write a typed helper

Easy

Write a function label(string $title, int $count): string that returns "CSS (16)" for those inputs.

PHP · starter

function label(string $title, int $count): string
{
}

Check your understanding before moving on.

Knowledge checkQuestion 1

Can a function read a variable defined outside it without passing it in?

Select an answer to continue

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Next: Arrays and loops

Lesson 3 of 300 · 0% of course