3v4l.org

run code in 300+ PHP versions simultaneously
<?php namespace Test { trait Base { public $config = []; function __construct($config = []) { $this->config = $config; } } class Config { use Base; } } namespace { $test = new Test\Config(['foo' => 'bar']); echo isset($test->config['foo']) ? 'Success: foo is set' : 'Error: foo is not set'; }
based on nNMJi
Output for 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.1 - 7.3.28, 7.4.0 - 7.4.16, 8.0.0 - 8.0.3
Success: foo is set
Output for 7.3.0
Error: foo is not set