'PHP version', 'mandatory' => true, 'condition' => version_compare(PHP_VERSION, '5.4.0', '>='), 'by' => 'Yii Framework', 'memo' => 'PHP 5.4.0 or higher is required.', ], [ 'name' => 'Reflection extension', 'mandatory' => true, 'condition' => class_exists('Reflection', false), 'by' => 'Yii Framework', ], [ 'name' => 'PCRE extension', 'mandatory' => true, 'condition' => extension_loaded('pcre'), 'by' => 'Yii Framework', ], [ 'name' => 'SPL extension', 'mandatory' => true, 'condition' => extension_loaded('SPL'), 'by' => 'Yii Framework', ], [ 'name' => 'MBString extension', 'mandatory' => true, 'condition' => extension_loaded('mbstring'), 'by' => 'Multibyte string processing', 'memo' => 'Required for multibyte encoding string processing.' ], [ 'name' => 'Intl extension', 'mandatory' => false, 'condition' => $this->checkPhpExtensionVersion('intl', '1.0.2', '>='), 'by' => 'Internationalization support', 'memo' => 'PHP Intl extension 1.0.2 or higher is required when you want to use advanced parameters formatting in \Yii::t(), IDN-feature of EmailValidator or UrlValidator or the yii\i18n\Formatter class.' ], ];