const target = { a: 1, b: 2 };
const source = { b: 4, c: 5 };

const returnedTarget = Object.assign(target, source);

also we can write empty {} brackets and set it empty object as a first argument

let method4 = JSON.parse(JSON.stringify(car))
// JSON.stringify(car)
// JSON.parse('{"mark":"Ford","model":"Raptor"}')

JSON.PARSE method just converts it into a string then parses so it can clone nested objects too

// rest operator

let {...method2} = car
// let {model, ...rst} = car
// let {model, ...car} = {year:"2017", ...car}

// spread operator

let method1 = {...car}
// method1 === car  // false
// method1.model = "F150"
// let sprd = {...car, color: "black", model:"ranger"}

 var parents = ["mom", "dad"]
  var children = ["mike", "jenny"]
  var family = parents.concat(children);

["mom", "dad", "mike", "jenny"]

var family = ["mom", "dad", "mike", "jenny"]
var fstr = family.join();

fstr =  "mom,dad,mike,jenny"

function hello() { alert('Hi there!'); }

setTimeout(hello, 5000)

setTimeout( function() { alert('Hi there!'); }, 5000 )

Configurable Attribute

Enumerable

Writable:

var christmasList = {mike:"Book", jason:"sweater" }

delete christmasList.mike;  // deletes the mike property

var school = {schoolName:"MIT"};
console.log("schoolName" in school);  // true because schoolName is an own property on the school object

console.log("schoolType" in school);  // false because  because we did not define a schoolType property on the school object

// Prints true because the school object inherited the toString method from Object.prototype. 
console.log("toString" in school);  // true