How to get the string name of the argument's type hint?

问题

Let us say we have this function:

function greetMe (string $name) {                                                                                                                                        
    echo '<br/>'.$name;                                                                                                                                                  
    echo '<br/>'.gettype($name);                                                                                                                                         
}                                                                                                                                                                        

As you can see, we can get the type of the parameter $name.
Now I am interested to know if there is a possibility, within the body of this function, to know that I declared the type string and not some other type. Any hints?

回答1:

In PHP 7 and later, you can use ReflectionParameter.getType.

Example #1 ReflectionParameter::getType() example

<?php
function someFunction(int $param, $param2) {}

$reflectionFunc = new ReflectionFunction('someFunction');
$reflectionParams = $reflectionFunc->getParameters();
$reflectionType1 = $reflectionParams[0]->getType();
$reflectionType2 = $reflectionParams[1]->getType();

echo $reflectionType1;
var_dump($reflectionType2);

The above example will output something similar to:

int
null

来源：https://stackoverflow.com/questions/51889701/how-to-get-the-string-name-of-the-arguments-type-hint