(PHP 7, PHP 8)
ReflectionFunctionAbstract::getReturnType — Gets the specified return type of a function
Gets the specified return type of a reflected function.
此函数没有参数。
Returns a ReflectionType object if a return type is
specified, null otherwise.
Example #1 ReflectionFunctionAbstract::getReturnType() example
<?php
function to_int($param) : int {
return (int) $param;
}
$reflection1 = new ReflectionFunction('to_int');
echo $reflection1->getReturnType();
以上例程会输出：
int
Example #2 Usage on built-in functions
<?php
$reflection2 = new ReflectionFunction('array_merge');
var_dump($reflection2->getReturnType());
以上例程会输出：
null
This is because many internal functions do not have types specified for their parameters or return values. It is therefore best to avoid using this method on built-in functions.