object.js

const person={
    name:"vikash",
    age:"34",
    gender:"male"
};
console.log(person,person.gender)  //will return whole and then only that specified element
//adding values in object
person.hobbies=["playing","dancing","pubg"];
person.rank="developer";
console.log(person)

//[]
console.log(person["name"]);
person["id"]= 34;
console.log(person);

//. vs []
let key = "email";
person[key]="pvickey663@gmail.com";
console.log(person,"--------------------------")

//print value of object using loop
//cannot iterate object using=> for of loop
for(let key in person){
    console.log(person[key]); //or
    console.log(`the key is ${key} and the value is ${person[key]}`); //or
    console.log(key," : ",person[key]);
}

//To return the value of an Object in array format=> Object.keys(person)
let NewArary=Object.keys(person)
console.log(NewArary);

//Add value in the form of key:value format

const key1="obj1";
const key2="obj2";

const value1="my val 1";
const value2="my val 2";

const obj={
    [key1]:value1,
    [key2]:value2
}
console.log(obj);

//spread ooperator in object adding object person and above obj
const newObj={...person,...obj};
console.log(newObj);

//to add values in object without keys
let newobj={...["items1","items","items3"]};
console.log(newobj, "------------------------------");

//object destructuring
const band={
    name:"skillix",
    age:"34",
    // genre:"bass"
}
// const bandname=band.name;

//... to add rest values in the form of object in different obj
const {name,age}=band; //write same names as keys
console.log(name);
//if you want to use new variable for the keys but cant use spread operator
let{name:bandname,age:bandage}=band;
console.log(bandage);

//___________Object Inside Array___________
const users=[{userid :1, username:"vikas", agee:34},
             {userid :2, username:"rakesh", agee:4},
             {userid :3, username:"mihu", agee:42}]
console.log(users)

for(let user of users){
    console.log(user)
}

//Array Object destructuring
const []=users; //clones the user object into array 

//using constructor target = users and as to destructure the values inside object
//we us {} to destructure from the object then seleting the required element
const[{userid:firstname},,{agee}]=users;  //will create two constant userid and agee
console.log(firstname,agee) //firstname is now refrencing to userid 


//OBJECT PRACTISE  with Methods()

function fullDescription(fname,lastname,email,age,address){
    let userInfo={};
    userInfo.fname=fname;
    userInfo.lastname=lastname;
    userInfo.email=email;
    userInfo.age=age;
    userInfo.address=address;
    userInfo.about = function(){
        return `Name is ${fname,lastname}, age is ${age}, email ${email}, address ${address}} `;
    };
    userInfo.is18=function(){
        return this.age>=18;
    };
    return userInfo; 
}

const user1=fullDescription("vikash","tilak","free@gmail.com",34,"mumbai");
console.log(user1);
const uerinfo=user1.about();
console.log(uerinfo);

// in above code ithe methods are getting created for evry user so it is bad practise for memory
// so let make a methos that initialize for only one time

const useMethods = {
    about : function(){
    return `Name is ${this.fname,this.lastname}, age is ${this.age}, email ${this.email}, address ${this.address} `},
    is18 :function(){
    return this.age >=18;
    }
}

function fullDesc(fname,lastname,email,age,address){
    let userInfo={};
    userInfo.fname=fname;
    userInfo.lastname=lastname;
    userInfo.email=email;
    userInfo.age=age;
    userInfo.address=address;
    userInfo.about = useMethods.about;
    userInfo.is18 = useMethods.is18;
    return userInfo; 
}

const myname=fullDesc("MAHABHARATA","malva","free@gmail.com",54,"mumbai");
const myname1=fullDesc("HSRETWEXz","gsgda","yahil.com",14,"bambai");
console.log(myname);
console.log(myname.about());
console.log(myname.is18());

//BUT ALSO IN THE ABOVE CODE YOU CAN SEE THAT WE HAVE TO STORE THAT FUNCTION REFERNCE INSIDE OUR MAIN FUCTION
//SO AS MANY TIMES WE ARE CREATING NEW METHOD WE HAVE TO ADD TAHT METHOD REFERENCE IN OUT FUNCTION NAME

// CALLING METHOS FROM ONE OBJECT TO ANOTHER
//****************    METHOS CHAINNING    ********************/

const OBJ1={
    key1 : "value1",
    key2 : "value2"
}
// there is one more way to create empty object
//will use that methos to create object chaning

const OBJ2=Object.create(OBJ1);

console.log(OBJ2);
OBJ2.key4="value4";
console.log(OBJ2.key1);

//**********  CHECK PROTOTYPR  **************/