(PHP 4 >= 4.2.0, PHP 5, PHP 7) Dumps a string representation of an internal zend value to output

(PHP 4 >= 4.0.4, PHP 5, PHP 7) Finds whether a variable is NULL

(PHP 4 >= 4.0.5, PHP 5, PHP 7) Finds whether a variable is a scalar

(PHP 5 >= 5.5.0, PHP 7) Get the boolean value of a variable

(PHP 4, PHP 5, PHP 7) Creates a PHP value from a stored representation

(PHP 4, PHP 5, PHP 7) Finds whether a variable is an object

(PHP 4, PHP 5, PHP 7) Finds whether a variable is a number or a numeric string

(PHP 4, PHP 5, PHP 7) Alias of

(PHP 4 >= 4.0.2, PHP 5, PHP 7) Returns the resource type

(PHP 4 >= 4.2.0, PHP 5, PHP 7) Outputs or returns a parsable string representation of a variable