ReflectionParameter::getDefaultValue Gets default parameter value &reftitle.description; public mixedReflectionParameter::getDefaultValue Gets the default value of the parameter for a user-defined function or method. If the parameter is not optional a ReflectionException will be thrown. &reftitle.parameters; &no.function.parameters; &reftitle.returnvalues; The parameters default value. &reftitle.examples; Getting getParameters() as $param) { echo 'Name: ' . $param->getName() . PHP_EOL; if ($param->isOptional()) { echo 'Default value: ' . $param->getDefaultValue() . PHP_EOL; } echo PHP_EOL; } ?> ]]> &example.outputs; &reftitle.notes; Due to implementation details, it is not possible to get the default value of built-in functions or methods of built-in classes. Trying to do this will result a ReflectionException being thrown. &reftitle.seealso; ReflectionParameter::isOptional ReflectionParameter::isPassedByReference