Introduction to Objects

JavaScript Tutorials - Herong's Tutorial Examples

∟Introduction to Objects

This chapter provides introductions and tutorial examples on the 'Object' data type in JavaScript. Topics include creating 'Object' objects; adding and retrieving properties; adding and running methods; named and indexed properties; comparing arrays with objects.

What Is an Object?

Objects of "Object" Data Type

Adding and Deleting Object Own Properties

Adding and Deleting Object Own Methods

Using "this" Keyword to Represent Current Object

Object Literals of the "Object" Type

Objects and Associate Arrays

Objects with Indexed Properties

Differences between "Object" and "Array"

Using "Array" Objects as "Object" Objects

Takeaways:

An object is an instance of a special data type called "Object" or any "prototype" data type.
"Object" data type is root "prototype" of all "prototype" data types.
A new object can be created using an object literal: {n:v, ...}.
A new object can be created using the Object constructor: New Object().
An object's property or method can be accessed using the dot "." operation.
An object's property or method can be deleted using the dot "delete" operation.
When defining the method body of an object, can you use the "this" keyword to refer to the object.
An object's property can be accessed as an element of an associated array.
An object can have indexed properties, similar to an array.
An array is an object.