The ReflectionFunction class

We can use this functionality to automatically pass arguments to our function based on some data structure.
NOTE: I am using a php 8.0> feature called "Nameds parameter"
<?php
$valuesToProcess = [
 'name' => 'Anderson Lucas Silva de Oliveira',
 'age' => 21,
 'hobbie' => 'Play games'
];
function processUserData($name, $age, $job = "", $hobbie = "")
{
 $msg = "Hello $name. You have $age years old";
 if (!empty($job)) {
 $msg .= ". Your job is $job";
 }
 if (!empty($hobbie)) {
 $msg .= ". Your hobbie is $hobbie";
 }
 echo $msg . ".";
}
$refFunction = new ReflectionFunction('processUserData');
$parameters = $refFunction->getParameters();
$validParameters = [];
foreach ($parameters as $parameter) {
 if (!array_key_exists($parameter->getName(), $valuesToProcess) && !$parameter->isOptional()) {
 throw new DomainException('Cannot resolve the parameter' . $parameter->getName());
 }
 if(!array_key_exists($parameter->getName(), $valuesToProcess)) {
 continue;
 }
 $validParameters[$parameter->getName()] = $valuesToProcess[$parameter->getName()];
}
$refFunction->invoke(...$validParameters);
?>

Results in:
Hello Anderson Lucas Silva de Oliveira. You have 21 years old. Your hobbie is Play games.

Here is a concise example of ReflectionFunction usage for Parameter Reflection / introspection (e.g. to automatically generate API descriptions)
<?php
$properties = $reflector->getProperties();
$refFunc = new ReflectionFunction('preg_replace');
foreach( $refFunc->getParameters() as $param ){
 //invokes ■しかくReflectionParameter::__toString
 print $param;
}
?>

prints:
Parameter #0 [ <required> $regex ]
Parameter #1 [ <required> $replace ]
Parameter #2 [ <required> $subject ]
Parameter #3 [ <optional> $limit ]
Parameter #4 [ <optional> &$count ]