Objects

Objects

const chandraPrakash = {
  firstName: 'ChandraPrakah',
  lastName: 'Darji',
  age: 2022 - 2002,
  job: 'Student',
  languages: ['JavaScript0', 'Python', 'Html', 'CSS'],
  drivingLicense: false,
  // can also hold a function beacuse function is a datatype
  calcAge: function (birthYear) {
    return 2022 - birthYear;
  },
  calcAgeThis: function () {
    return 2022 - this.birthYear; // Takes value from object
  },
  getSummary: function () {
    console.log(
      `${this.firstName} is a ${
        this.job
      } of ${this.calcAgeThis()} learnig today ${this.languages[0]} with ${
        this.drivingLicense ? 'a' : 'no'
      } driving License`
    );
  },
};
console.log(chandraPrakash);

// Calling function
console.log(chandraPrakash.calcAge(2002));
console.log(chandraPrakash.calcAgeThis());
chandraPrakash.getSummary();

// Accesing Element
console.log(chandraPrakash.firstName); // Dot Notation
console.log(chandraPrakash['job']); // Bracket Notation

// In Bracket Notation Expresion are Allowded
const nameKey = 'Name';
console.log(chandraPrakash['first' + nameKey]);
console.log(chandraPrakash['last' + nameKey]);

// Adding a Element in Objects
chandraPrakash.location = 'india';
chandraPrakash['twitter'] = '@chandra_7852';

// Copying the Object
const jessica = {
  firstName: 'Jessica',
  lastName: 'Willams',
  age: 27,
};
const jessicaMarried = jessica;
console.log(jessica); // {firstName: 'Jessica', lastName: 'Willams', age: 27}
console.log(jessicaMarried); // {firstName: 'Jessica', lastName: 'Willams', age: 27}
jessicaMarried.lastName = 'Dave';
console.log(jessica); // {firstName: 'Jessica', lastName: 'Dave', age: 27}
console.log(jessicaMarried); // {firstName: 'Jessica', lastName: 'Dave', age: 27}
// this will essentially just point to same object ... same object with diffrent names ...
const jessica2 = {
  firstName: 'Jessica',
  lastName: 'Willams',
  age: 27,
  family: ['Bob', 'Steven'],
};
const jessica2Married = Object.assign({}, jessica2);
console.log(jessica2); // {firstName: 'Jessica', lastName: 'Willams', age: 27}
console.log(jessica2Married); // {firstName: 'Jessica', lastName: 'Willams', age: 27}
jessica2Married.lastName = 'Dave';
console.log(jessica2); // {firstName: 'Jessica', lastName: 'Willams', age: 27}
console.log(jessica2Married); // {firstName: 'Jessica', lastName: 'Dave', age: 27}
// This will create new object by combining 2 Objects ...

jessica2Married.family.push('Mary', 'John');
console.log(jessica2); // {firstName: 'Jessica', lastName: 'Willams', age: 27, family: Array(4)}
console.log(jessica2Married); // {firstName: 'Jessica', lastName: 'Willams', age: 27, family: Array(4)}
// Object.assign only work for first level... in this Both object array is changed ...
// to copy prefectly you need to do deep clone

// Destrucutring Object
const restaurant = {
  name: 'Classico Italiano',
  location: 'Via Angelo Tavanti 23, Firenze, Italy',
  categories: ['Italian', 'Pizzeria', 'Vegetarian', 'Organic'],
  starterMenu: ['Focaccia', 'Bruschetta', 'Garlic Bread', 'Caprese Salad'],
  mainMenu: ['Pizza', 'Pasta', 'Risotto'],

  openingHours: {
    thu: {
      open: 12,
      close: 22,
    },
    fri: {
      open: 11,
      close: 23,
    },
    sat: {
      open: 0, // Open 24 hours
      close: 24,
    },
  },
  order: function (starterIndex, mainIndex) {
    return [this.starterMenu[starterIndex], this.mainMenu[mainIndex]];
  },
  orderDelivery: function ({
    starterIndex = 0,
    mainIndex = 1,
    time = '20:00',
    address,
  }) {
    console.log(
      `Order Recived! ${this.starterMenu[starterIndex]} and ${this.mainMenu[mainIndex]} will be delivered to ${address} at ${time}`
    );
  },
  orderPasta: function (ing1, ing2, ing3) {
    console.log(
      `Here is Your delecious Pasta with ${ing1} , ${ing2} and ${ing3} ::: `
    );
  },
};
const { name, openingHours, categories } = restaurant;
console.log(name, openingHours, categories); // variable name should exactly same as in Object
const {
  // Unpacking with diffrent variable Name
  name: restaurantName,
  openingHours: hours,
  categories: tags,
  breakMenu: menu = 'No Data', // default value if data no Exist
} = restaurant;
console.log(restaurantName, hours, tags, breakMenu);

// Mutating variables
let a = 10,
  b = 20;
const obj = { a: 42, b: 65, c: 86 };
({ a, b } = obj);
console.log(a, b);

// Nested Objects
// Method 1
const { open: openFri, close: closeFri } = openingHours.fri;
console.log(openFri, closeFri);
// Method 2
const {
  openingHours: {
    fri: { open: o, close: c },
  },
} = restaurant;
console.log(o, c);

// Unpacking Use in Functions -> no More variable to specifiy as pparameter just one object -> then it will be unpacked
restaurant.orderDelivery({
  time: '22:30',
  address: '402, Saheli Tailor',
  mainIndex: 2,
  starterIndex: 2,
});
restaurant.orderDelivery({
  address: '402, Saheli Tailor',
});

// Spread Oprator in Object Use
const ingredient = [
  prompt("Let's make Pasta! Ingredient 1:"),
  prompt('Ingredient 2:'),
  prompt('Ingredient 3:'),
];
// Both will work
restaurant.orderPasta(ingredient[0], ingredient[1], ingredient[2]);
restaurant.orderPasta(...ingredient);
// Spread operator will work Better

// ES2018 we can use ... spread opertor on Objects
const newRestaurant = { ...restaurant, founder: 'Gessiuf', founderYear: 1994 };
console.log(newRestaurant);

// Copying the Object
const restaurantCopy = { ...restaurant };
restaurantCopy.name = 'Ristornos Roma';
console.log(restaurantCopy);

// Enhanced object litteral
const weekdays = ['mon', 'tue', 'wed', 'thu', 'sat', 'sun'];

const openingHours = {
  // property name can be modified now by expression
  [weekdays[3]]: {
    open: 12,
    close: 22,
  },
  [weekdays[4]]: {
    open: 11,
    close: 23,
  },
  [weekdays[5]]: {
    open: 0,
    close: 24,
  },
  [`day ${1 + 2 + 3}`]: {
    open: 8,
    close: 22,
  },
};
const school = {
  schoolName: 'Mark Socitey',
  hours, // ES6 enhanced object literal
  sorderPasta(ing1, ing2, ing3) {
    // no need for function keyword and semi colon
    console.log(
      `Here is Your delecious Pasta with ${ing1} , ${ing2} and ${ing3} ::: `
    );
  },
};
console.log(school);

// Without optional chaining
if (restaurant.openingHours && restaurant.openingHours.mon)
  console.log(restaurant.openingHours.mon.open);

console.log(restaurant.openingHours.mon.open); // with throw the error of  Cannot read properties of undefined (reading 'open')

// WITH Opetional Chaining
console.log(restaurant.openingHours.mon?.open); // here it wil check if restaurant.openingHours.mon it exist then and only the .openn will bw readed

////////////////////////////////////
// Without optional chaining
if (restaurant.openingHours && restaurant.openingHours.mon)
  console.log(restaurant.openingHours.mon.open);

console.log(restaurant.openingHours.mon.open); // with throw the error of  Cannot read properties of undefined (reading 'open')

// WITH Opetional Chaining
console.log(restaurant.openingHours.mon?.open); // here it wil check if restaurant.openingHours.mon it exist then and only the .openn will bw readed
console.log(restaurant.openingHours?.mon?.open);
*/
// Examples
const days = ['mon', 'tue', 'wed', 'thu', 'sat', 'sun'];
for (const day of days) {
  const open = restaurant.openingHours?.[day]?.open ?? `closed`;
  console.log(`On ${day} we open at ${open}`);
  /* Output ::: On mon we open at closed
                On tue we open at closed
                On wed we open at closed
                On thu we open at 12
                On sat we open at 11
                On sun we open at 0
*/
}
// Methods
console.log(restaurant.order?.(0, 1) ?? `Method does not exist`); // ['Focaccia', 'Pasta']
console.log(restaurant.orderRissato?.(0, 1) ?? `Method does not exist`);


//////////////////////////////////////
// Looping the Objects
// Display Keys only
const properties = Object.keys(openingHours);
console.log(properties);

let openStr = `We are open o  ${properties.length} days: `;
for (const day of properties){
  openStr+=`${day}, `
}
console.log(openStr);

// Property VALUES
const values = Object.values(openingHours)
console.log(values);

// Entire Object
const entries = Object.entries(openingHours)
console.log(entries);

for (const [day, {open,close}] of Object.entries(openingHours)){
  console.log(`On ${day} we open at ${open} and close at ${close}`);
}