An object is an collection value and key pair.

Creating Objects

• we use curley brackets {} or object literal to create object. ex-

  let user = {
  name: "John",
  age: 18
  isAdult: true
  }
  

Different Operations perform in objects

1. Accessing a value
2. Adding a new property
3. Updating a value
4. Deleting the property

Accessing a value

For accessing value from an object.

we use 2 operator

• Dot Operator
• Sqaure brakcet operator

Dot Operator( . )

The dot Operator does only one things is to access the value

ex-

let user = {
name: "John",
age: 18
isAdult: true
}
user.name
"John"

Square brackets( [] )

The square brackets does two things computes the value and access it

when to use square brackets??

• when there is space
• other symbol or number
• or it is stored in a varibale we use it

ex

let user = {
name: "John",
age: 18
isAdult: true
}


user[name]
"John"

Adding a new property

To Add new property

• name of the object follwed by dot ( . ) operator
• name of the key

ex-

- Using dot operator
user.city = "London"
"London

- Using sqaure bracket
user["batch"] = 8
"batch"

if we access user

user

age: 18
city: "london"
name: "John"
isAdult: true

Updating a value

• When the key doesn`t exist it create new property
• if key exist it will update the property

ex-

user.age = 26
<. 26

if we access the user
user: 

age: 26 (age is update from 18 to 24)
city: "London"
batch: 8
is Adult: true
name: "John"

Deleting a Key

• delete is speacial keyword to delete a property of an object.
• delete followed by name of object and key want to delete

ex-

delete use.city
<. true

user

age: 26 (age is update from 18 to 24)
batch: 8
is Adult: true
name: "John"

city key and value is deleted

Rules for naming the key in an object

• when key is an single word don`t put in double quote
• whenever you have multiple word keyname remeber to put in double quotes( " " )
• if you don`t put in double quotes( " " ) it shoes an error.