VIDEO 42 in JS

/****************  OOPS IN JAVASCRIPT *************************/

/* JAVASCRIPT AND CLASSES 
So yes, JavaScript does have classes, and they are quite powerful for object-oriented programming!

/* OOP 

/*Object 
-collection to properties  and methods 
-ex: toLowerCase 

/* parts of oops
Object literal means literally assinged 

-constructor functions 
-prototypes 
-classes n
-Instances 

/* 4 pillars 
abstraction 
encaplusation 
inheritnace 
polymoriphism 
*/

const user = { // object literal 
    username: "hitesh ",
    logincount: 8,
    signedIn: true,

    getUserDetails: function() {
        console.log(`username: ${this.username}`);
        console.log(this); 
        /* output : {
  username: 'hitesh ',
  logincount: 8,
  signedIn: true,
  getUserDetails: [Function: getUserDetails]*/
}
    }

console.log(user.getUserDetails()); // username: hitesh //undefined
console.log(this); // {}

/////////////// CONSTRUCTOR FUNCTION //////////////
function User2(username, logincount, isLoggedIn) {
  this.username = username;
  this.logincount = logincount;
  this.isLoggedIn = isLoggedIn;
  
  this.greeting = functio
return this
}

const userOne =/*HERE new TO FIX THE ERROR*/ User2("hitesh", 12, true);
const userTwo = /*HERE new TO FIX THE ERROR*/User2("hitesh chaudhary", 18, false)
 console.log(userOne);   
/*username: 'hitesh chaudhary',
  logincount: 18,
  isLoggedIn: false*/ 
  /* INPORTANT == IF WE USE NEW IN DECLARATION SPACE IT WILL RUNCORRECTLY */ 
  
  /* INPORTANCE  and FEATURES OF NEW KEYWORD === when we use new keyword new empty object is made in first step , it will  call the constructor function in second step  , it will inject all the values which we passed in arguments , than it will return to you */