Objects

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  • objects is a collections of data . objects represent by { ... } or array objects [{},{}] . objects is name value pair base.

create objects

  • constructor
let users = new Object()
  • literal object with square bracket {..}
let users = {
  ......
}

let users = {
  name: 'kamal',
  age: 21,
  phone: 8123
}
console.log(users.name);
// kamal

let users = {
  name: 'kamal',
  age: 21,
  phone: {
    home: 88012,
    office: 121
  }
}
console.log(users.phone.office);
// 121

let users = [
  {name: 'kamal', age: 21},
  {name: 'jamal', age: 23},
  {name: 'maruf', age: 6}
]
users.forEach((user) => {
  console.log(user.name);
})
// kamal , jamal , maruf
  • es6 loop
let users = [
  {name: 'kamal', age: 21 ,post: 'marketer'},
  {name: 'jamal', age: 23, post: 'civil'},
  {name: 'maruf', age: 6, post: 'ceo'}
]
 for (let {name,post} of users) {
  console.log(`${name} is posted as ${post}`);
}
// kamal isposted as marketer
// jamal is posted as civil
// maruf is posted as ceo

multiword property

set

let users = {
  name: 'kamal',
  age: 21,
  phone: 017
}
users['salary rate'] = 2000;
console.log(users);
// {name: "kamal", age: 21, phone: 15, salary rate: 2000}

get

let users = {
  name: 'kamal',
  age: 21,
  phone: 017
}
users['salary rate'] = 2000;
console.log(users['salary rate']);
// 2000

delete

let users = {
  name: 'kamal',
  age: 21,
  phone: 017
}
users['salary rate'] = 2000;
delete users['salary rate'];
console.log(users['salary rate']);
// undefined
// deleted

method lists

methods methods methods
Object.assign() Object.create() Object.defineProperty()
Object.defineProperties() Object.entries() Object.freeze()
Object.getOwnPropertyDescriptor() Object.getOwnPropertyDescriptors() .
Object.getOwnPropertyNames() Object.getOwnPropertySymbols() Object.values()
Object.getPrototypeOf() Object.is() Object.isExtensible()
Object.isFrozen() Object.isSealed() Object.keys()
Object.preventExtensions() Object.seal() Object.setPrototypeOf()

assign

  • copy / clone
  • target ... source
let users = {
  name: 'kamal',
  age