filter_var php question

Question

I am making a quick little email script for a contact form and these variable aren't being set($firstName and $lastName).

$firstName = filter_var($_POST['firstName'], FILTER_SANITIZE_STRING);
$lastName = filter_var($_POST['lastName'], FILTER_SANITIZE_STRING);

Note I am a beginner at php

Answer 1

You're a beginner? Well, hats off to you for using data validation from the get-go!

can you put this below those two lines and give us the output?

var_dump($firstName, $lastName, $_POST);