What is the initial value of a variable?

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

Is the following code valid?

Which will return the complete URL of the requested PHP page?

What is the output?

What is the output?

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

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

'virtual()' in PHP

Which does not have a resource for a return type?

When passing an object to json_encode(), the default behavior can be modified by: