PHP Basics: What’s an Object?

What is an object?

In PHP (and Joomla), an object is like a box that holds multiple values (called properties) and functions (called methods). An object is a suitcase full of useful info. You just have to open it and see what’s inside.

Example: The $article Object

When you load an article in Joomla, Joomla stores it in a variable like this:

$article = $this->item;

This $article is an object, and it contains all the info about that article:

• Title

• Intro text

• Author

• Publish dates

• Category

• And more!

How do we know what’s inside?

Use var_dump() or print_r() to look inside:

<?php
var_dump($article);
?>

That shows:

object(stdClass)#123 (15) {
  ["id"] => int(101)
  ["title"] => string(20) "Hello World Article"
  ["alias"] => string(11) "hello-world"
  ["introtext"] => string(250) "<p>Welcome to Joomla!</p>"
  ...
}

Accessing a property

Once you know what’s inside, you can grab individual values using the arrow syntax ->:

<?php
echo $article->title;       // Shows the article title
echo $article->introtext;   // Shows the intro text
?>

Common $article Properties