What is the default timeout of a PHP session cookie ?

What's the output? $one='two'; $two='one'; echo $$$one;

Result of calling json_encode() on an empty array?

What is the output of the following code? $a='20' $a -= 5; echo $a++;

Given the following code: printVar(); ?> What will the output be?

When adding ('+' function) two variables of type integer and type string, what type is the resulting value?

What is the output?

Output of the code? ' ?>'

Which is not related to debugging in PHP?

Output of the code?

Which features are supported in PHP5?