Types

Types

Jeffrey

The Object (compound) Type

Like every programming language, PHP offers the usual basic primitive types which can hold only one piece of data at a time (scalar). I am particularly fond of the "object" type (compound) because that allows me to group many basic PHP types together, and I can name it anything I want.

class Person
{
  $firstName;                   // a PHP String
  $middleName;                  // a PHP String
  $lastName;                    // a PHP String
  $age;                         // a PHP Integer
  $hasDriversLicense;           // a PHP Boolean
}
?>

Here, I have grouped several basic PHP types together, (3) Strings, (1) Integer, and (1) Boolean... then I named that group "Person". Since I used the proper syntax to do so, this code is pure PHP, which means that if you run this code, you would have an extra PHP "type" available to you in your scripts, like so:

$myAge = 16;                    // a PHP Integer - always available
$yourAge = 15.5;                // a PHP Float   - always available
$hasHair = true;                // a PHP Boolean - always available
$greeting = "Hello World!"      // a PHP String  - always available

$person = new Person();         // a PHP Person  - available NOW!
?>

You can make your own object types and have PHP execute it as if it were part of the PHP language itself. See more on classes and objects in this manual at: http://www.php.net/manual/en/language.oop5.php

arjini at gmail dot com

Note that you can chain type castng:

var_dump((string)(int)false); //string(1) "0"

shahnaz khan

if we use gettype() before initializinf any variable it give NULL
for eg.

$foo;
echo gettype($foo);
?>

it will show

NULL