"virtual()" in PHP

How to get the number of arguments passed to a PHP function?

$a = array('a' => 0, 'b' => 0, 'c' => 1, 'd' => 2); $b = array_flip($a); var_dump($b); What does the 'var_dump' function show ?

use keyword is used only for namespace

What's the output? array_map('print_r', array( 'a', 'b' ) );

Use of the final keyword in a method declaration prevent?

Is the following code valid?

Which will not return an array containing all normal Latin alphabet characters (A-Z)?

Initial value of a variable?

What is meant by Synchronous Server Calls within PHP's cURL features?

Fastest way to insert an item $item into the specified position $position of the array $array?