PHP Version Compatibility

How it works

Function availability is only one diagnostic: an absent function can mean a missing extension, a removed API or a different build. Available functions can still be deprecated or inappropriate for the task. PHP 8 removed several historical helpers, while PHP 8.4 deprecates relying on the default CSV escape parameter. This course uses current alternatives and labels the optional property-hook lesson as PHP 8.4+. Consult the exact official migration/function entry rather than inferring every version rule from a presence check.

Run it locally

Run this complete source locally with PHP 8.2 or newer. Save it using the filename shown and run the command below. PHP is not currently available in Bhylu’s browser playground. Apache and MySQL are not needed for an ordinary CLI example.

php -l ref-compatibility.php
php ref-compatibility.php

Download this source as a local PHP lab file. Keep lab files separate from the Bhylu project and production data.

Example

<?php
declare(strict_types=1);

echo function_exists("each") ? "Legacy each available\n" : "Use foreach instead of removed each\n";
echo function_exists("password_hash") ? "Password API available\n" : "Missing password API\n";
echo class_exists(ZipArchive::class) ? "ZipArchive available\n" : "Enable ZIP for archive labs\n";

Expected result

Use foreach instead of removed each
Password API available
ZipArchive available

The first result matches the PHP 8 review runtime. The other two inspect capabilities without sending mail, opening a transfer or extracting an archive. A deployment check should require only the extensions actually used by its chosen features and keep unsupported features clearly labelled.

Contracts to check