Object - Javascript

Object used to store multiple values in a single variable using key-value pairs.

const person = {

     name : "Sherin",
     age : 25,
     role : "Software Tester"
};
console.log(person);

*OutPut *

`{name: 'Anees', age: 23, role: 'Software Tester'}`

Object Properties :

1.Dot Notation :

`console.log(person.name);
console.log(person.age);`

OutPut

`Sherin
25`

2.Bracket Notation :

`console.log(person["Role"]);`

OutPut

`Software Testing`

3.Add New Properties :

`person.country = "India";
console.log(person);`

*OutPut *

`{
  name: "Sherin",
  age: 23,
  role: "Software Tester",
  country: "India"
}`

4.Updating Properties :

`person.age = 24;
console.log(person.age);`

*OutPut *

`24`

5.Deleting Properties :

`delete person.role;
console.log(person);`

OutPut

`{
  name: "Sherin",
  age: 24,
  country: "India"
}`

Object with Method

object can contain functions.
`const student = {
  name: "Sherin",

  greet() {
    return `Hello, I'm ${this.name}`;
  }
};

console.log(student.greet());`

OutPut

`Hello, I'm Sherin`

Nested Objects

Objects can contain other objects.

`const employee = {
  name: "Sherin",
  address: {
    city: "Chennai",
    pincode: 600001
  }
};

console.log(employee.address.city);`

OutPut

`Chennai`

Object Methods

1.Object.keys()
Returns all keys.

`console.log(Object.keys(person));`

OutPut

`["name", "age", "country"]`

2.Object.values()
Returns all values.

`console.log(Object.values(person));`

OutPut

`["Sherin", 24, "India"]`

3.Object.entries()
Returns key-value pairs.

`console.log(Object.entries(person));`

OutPut

`[
  ["name", "Anees"],
  ["age", 24],
  ["country", "India"]
]`

Object Spread Operator

Merge the objects.

`const personal = {
  name: "Sherin",
  age: 25
};

const professional = {
  role: "Software Tester",
  country: "India"
};

const profile = {
  ...personal,
  ...professional
};

console.log(profile);`

OutPut

`{
  name: "Sherin",
  age: 23,
  role: "Software Tester",
  country: "India"
}`