In this Article We define, and work with objects.
- You can also initialize an object with key-value pairs when you create it.
- Deleting a Key-value pair
key value pair
var books = { name: "Blue Highways" }; // or, equivalently var books = new Object({ name: 'Blue Highways' })
In this case, name
is the key and "Blue Highways"
is the value.
Note that all keys in JavaScript objects are strings.
- This means that even though you can create an object
name: 'Eat, Pray, Love: One Woman's Search for Everything Across Italy, India and Indonesia'
.- The key here,
name
gets turned into the string'name'
. Values can be of any type.
var book = { name: "Blue Highways", name: "Unlikely Destinations: The Lonely Planet Story" }
And then check on the value of book
, you’d see
{ name: "Unlikely Destinations: The Lonely Planet Story" }
Only the last key-value pair to use name
as the key gets saved! Values don’t have to be unique, though
var book = { name: "Blue Highways", author: "William Least Heat-Moon", year: 1982 }
Deleting a Key-Value Pair
If We want to delete the year key-value pair
var book = { name: "Blue Highways", author: "William Least Heat-Moon", year: 1982 } // the
delete
operator returnstrue
if it has successfully // deleted,false
otherwise delete book.year; // true book; // returns { author: "William Least Heat-Moon", name: "Blue Highways" }