Object In JS

An object is a collection of properties, and a property is an association between a key and a value.

### Decleration

An empty object can be created using one of two syntaxes:
let user = new Object();
let user = {};

### How To Access A object

let user = {   
   name: "Tom",
   age: 30 
} 
console.log(user.name);
// Tom

Method in Object

### assign

const target = { a: 1, b: 2 };
const source = { b: 4, c: 5 };
const returnedTarget = Object.assign(target, source);
console.log(returnedTarget);
// { a: 1, b: 4, c: 5 }

### create

const person = {
  introductionYourself: function() {
    console.log(`My name is ${this.name}.`);
  }
};
const me = Object.create(person);
me.name = 'Piter'; 
// "name" is a property set on "me", but not on "person"
me.introductionYourself();
// "My name is Piter."

### defineProperties

const object1 = {};
Object.defineProperties(object1, {
  property1: {
    value: 45
  },
  property2: {
    value: 'Piter'
  }
});
console.log(object1.property1);
// 45
console.log(object1.property2);
// "Piter"

### defineProperty

const object1 = {};
Object.defineProperty(object1, 'property1', {
  value: 42,
  writable: true
});
console.log(object1.property1);
// 42

### entries

const object1 = {
  a: 'somestring',
  b: 42,
  c: false
};
for (const [key, value] of Object.entries(object1)) {
  console.log(`${key}: ${value}`);
}
// expected output:
// "a: somestring"
// "b: 42"
// "c: false"

### freeze

const obj = {
  name:"Piter"
};
Object.freeze(obj);
obj.name = "Harry";
// Throws an error in strict mode
console.log(obj.name);
//  "Piter"

### isFrozen

const object1 = {
  property1: 42
};
console.log(Object.isFrozen(object1));
// false
Object.freeze(object1);
console.log(Object.isFrozen(object1));
// true

### fromEntries

const obj = {
const entries = new Map([
  ['foo', 'bar'],
  ['baz', 42]
]);
const obj = Object.fromEntries(entries);
console.log(obj);
// { foo: "bar", baz: 42 }

### keys

const object1 = {
  a: 'somestring',
  b: 42,
  c: false
};
console.log(Object.keys(object1));
// Array ["a", "b", "c"]

### hasOwnProperty

const object1 = {
 property1 : 42
};
console.log(object1.hasOwnProperty('property1'));
// expected output: true
console.log(object1.hasOwnProperty('property2'));
// expected output: false

### seal

const object1 = {
  property1: 42
};
Object.seal(object1);
object1.property1 = 33;
console.log(object1.property1);
// 33
delete object1.property1; // can't delete when sealed
console.log(object1.property1);
// 33

### values

const object1 = {
  a: 'somestring',
  b: 42,
  c: false
};
console.log(Object.values(object1));
// Array ["somestring", 42, false]