ReflectionParameter::getDefaultValueConstantName Returns the default value's constant name if default value is constant or null &reftitle.description; public stringnullReflectionParameter::getDefaultValueConstantName Returns the default value's constant name of the parameter of any user-defined or internal function or method, if default value is constant or null. If the parameter is not optional a ReflectionException will be thrown. &reftitle.parameters; &no.function.parameters; &reftitle.returnvalues; Returns string on success or &null; on failure. &reftitle.changelog; &Version; &Description; 8.0.0 This method now allows getting the default values' constant names of built-in functions and built-in class methods. Previously, a ReflectionException was thrown. &reftitle.examples; Getting default values' constant names of function parameters getParameters() as $param) { echo 'Name: ' . $param->getName() . PHP_EOL; if ($param->isOptional()) { echo 'Default value: ' . $param->getDefaultValueConstantName() . PHP_EOL; } echo PHP_EOL; } ?> ]]> &example.outputs; &reftitle.seealso; ReflectionParameter::isOptional ReflectionParameter::isDefaultValueConstant ReflectionParameter::getDefaultValue