Match Expressions

Quick Introduction

Match Expressions is a single PHP idea you'll use in almost every backend project.

In this lesson you learn only match expressions — not five topics at once. By the end you can write a small working example and explain it in an interview.

We connect each lesson to our course projects: Login System, Blog CMS, REST API, Inventory, Employee Management, and E-Commerce Backend.

Business Problem

You're building the REST API. After a user signs in, you need match expressions working correctly before storing data or showing a dashboard.

Without understanding Match Expressions, the team ships bugs: wrong totals, broken sessions, or type errors that only appear in production. This lesson fixes that with one clear pattern you can copy into your project today.

Core Concept

• Match Expressions is one focused idea — learn it before mixing with other PHP topics.
• Use it in PHP 8.3+ with declare(strict_types=1); at the top of every file.
• Our course project (REST API) uses match expressions in real handlers.
• Run small scripts with php file.php after each change — don't just read.
• Interviewers ask for a one-minute explanation plus a tiny code sample.

Syntax

Core syntax for Match Expressions. Every keyword below appears in production PHP — Laravel and Symfony use the same primitives under the hood.

declare(strict_types=1);

Keywords: declare · strict_types · namespace

Step-by-Step Example

Run this script locally. Change one value, run again, and watch what changes.

<?php
declare(strict_types=1);

enum HttpStatus: int { case Ok = 200; case Created = 201; case NotFound = 404; case ServerError = 500; }

function describe(HttpStatus $status): string {
    return match ($status) {
        HttpStatus::Ok, HttpStatus::Created => 'Success response',
        HttpStatus::NotFound                => 'Resource missing',
        HttpStatus::ServerError             => 'Retry with backoff',
    };
}

function statusFor(?array $result): HttpStatus {
    return match (true) {
        $result === null       => HttpStatus::NotFound,
        isset($result['error']) => HttpStatus::ServerError,
        default                => HttpStatus::Ok,
    };
}

echo describe(statusFor(['id' => 1]));

Line by line

1. — part of the match expressions example; run the file to see the result.
2. declare(strict_types=1); — turns on strict type checking for this file.
3. enum HttpStatus: int { case Ok = 200; case Created = 201; case NotFound = 404; case ServerError = 500; } — part of the match expressions example; run the file to see the result.
4. function describe(HttpStatus $status): string { — part of the match expressions example; run the file to see the result.
5. return match ($status) { — part of the match expressions example; run the file to see the result.

User #42 (user@example.com) balance $19.99

Real-World Example

In the REST API, match expressions appears in a single request handler — not spread across ten files. Keep the example small, test it with php, then paste the pattern into your project branch.

<?php
declare(strict_types=1);

// TODO: Match Expressions exercise for REST API