How should you filter variables before passing to header()?

Which variable type can NOT be used as a type hint?

What's the output? 'green', 'red', 'blue'); $array2 = array('b' => 'green', 'yellow', 'red'); $result = array_intersect($array1, $array2); print_r($result); ?>

$a = array('pomme', 'banane'); $b = array(1 => 'banane', '0' => 'pomme'); var_dump($a === $b); What does-it print ?

How do you instantiate a new object from class foo? class foo { function do_foo() { echo 'Doing foo.'; } }

What's the output: $a = true; echo (is_null($a)) ;

What will be the output of the following PHP code? <?php $fruits = array ("mango", "apple", "peach", "pear"); $fruits = asort ($fruits); printr ($fruits); ?>

Which number of primitive types does PHP support?

What's the output? $a = 'clue'; $a .= 'get'; echo '$a';

What is the standard PHP function to send emails?