Migrating a PHP Application from 7.4 to 8.3

A multi-version upgrade must audit PHP 8.0–8.3 changes, dependencies and deprecated APIs.

What It Does and When to Use It

The match expression requires PHP 8.0+ and uses strict comparison. A minimum platform requirement controls what syntax can be parsed; target-version tests find runtime and extension incompatibilities.

Requirements, Inputs and Expected Behavior

Confirm the runtime, extension, environment variables, and permissions before running the examples in production. Test every intermediate compatibility issue, especially strict comparisons and dynamic properties.

Example 1: Basic Operation

The match expression requires PHP 8.0+ and uses strict comparison.

<?php
$status = match (2) { 1=>'pending', 2=>'paid', default=>'unknown' }; echo $status;

Example 2: Behavior and Validation

Verify runtime and platform requirements before touching production.

php -v
php -l public/index.php
composer check-platform-reqs

Practical Example: Application Use

Validate dependency constraints, audit vulnerabilities and run regression tests.

composer validate --strict
composer audit --locked
vendor/bin/phpunit --testsuite unit

Important Behavior and Edge Cases

The second example highlights: Verify runtime and platform requirements before touching production. The practical example adds: Validate dependency constraints, audit vulnerabilities and run regression tests.

Comparison with Related Approaches

Common Beginner Mistakes

Key Takeaways

• A multi-version upgrade must audit PHP 8.0–8.3 changes, dependencies and deprecated APIs.
• Validate dependency constraints, audit vulnerabilities and run regression tests.
• Do not introduce syntax from a newer minor version before every production host supports it.