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 returns true if it has successfully
// deleted, false otherwise
delete book.year; // true

book;
// returns {  author: "William Least Heat-Moon", name: "Blue Highways" }

What is a Key-Value Pair?

key value pair

Deleting a Key-Value Pair