PolyfillOfarrayMethod.js

// Advanced Javascript

// const object1  = {
//     name: 'adam',
//     lastName: "gilchrist",
//     printName: function () {
//         console.log("hey" ,this.name ,"hey" ,this.lastName)
//     }
// }

// const object2 = {
//     home: "bnaxv",
//     adress: 'hvs gx'
// }

// object2.__proto__ = object1;
// console.log('after assigning proto')

// object2.printName();

// console.log(object2.lastName)
// console.log(object2.name)

// console.log(object1 , "Hye fine na")
// console.log(object2.valueOf() , "Hye fine na")

// // what can be the value of prototype => object  can be null

// const p1company  = {
//     name: "Witviper",
//     GSTNO: 'GZXTPRETZ',
//     set CompanyName(name) {
//      this.name  = name
//     } ,
//     get CompanyName () {
//         return this.name + ' ' + this.GSTNO
//     }
// }

// const p2company  = {
//     __proto__: p1company,
//     isChild: true,
// }

// const grandChild  = {
//     __proto__: p2company,
// }

// console.log(grandChild.name)

// grandChild.CompanyName = "Chilta pvt ltd."

// console.log(grandChild.name) //
// console.log(p1company.name)

// // will the context of this will be changed on the protoype  => No

// //
// const obj1 = {
//     1: "Hey ",
//     2: 'Hello',
//     3: 'Good morning'
// }

// const obj2 = {

// }

// const obj3 = {

// }

// const obj4 = {

// }

// Object.prototype.print = function () {
//     console.log('Print me')
// }

// const obj5 = {

// }

// obj5.print();
// obj4.print();
// obj3.print();
// obj2.print();
// obj1.print();

// console.log(obj4)

// const ob6 ={

// }

// ob6.print();

// // findAverageofGivernArray

// const array123 = [3,4,5,6,7];
// // console.log(array123.average());

// Array.prototype.average = function(){
//    let sum  = 0;
//    for(let i=0;i<this.length;i++) {
// sum = sum+this[i];
//    }
//    return sum/this.length
// }

// const avg = array123.average();
// console.log(avg)

// const avg2=[3,4,5,6,7,78].average();
// console.log(avg2)

// console.log([])

// String.prototype.stylisPrint = function() {
//     console.log('i am stylish print' , this)
// }

// const message = 'Hey we are learning prototype';

// message.stylisPrint()

// //  we have mutiple browser
// // some browser does not support new features of javascript

// // we need to create our own functions of features on that scenarion
// // that is called the pollyfill

// // creating your map filter  reduce  forEACH , BIND , CALL , APPLY
// // FLATTEN ARRAY

// Array.prototype.includesOneOf = function (list) {
//     if(list.length === 0  ||  this.length===0) return false;
//     for(let  i=0;i<this.length;i++) {

//         if(Array.isArray(list[0]) && Array.isArray(this[0])) {
//             for(let j=0;j<list.length;j++) {
//                 const che =  this[i];
//                 const che1 = list[j];
//                 if(che.length === che1.length && che.every((item ,index)=> {return item == che1[index]})) {
//                     return true
//                 }
//             }
//         }
//     //    else if(typeof this[0] === "object" && typeof list[0]){

//     //     }
//     else if(list[0].constructor == 'Object' && list[0].constructor == 'Object')
//         else {
//             if(list.includes(this[i])) {
//                 return true;
//             }
//         }
//     }
//     return  false;
// }

// const arr1 = [1,2,3,4];
// const arr2 =  [3,4,5,6];

// const arr3 = ["hello","hello2","checking","perfect"];
// const arr4 =  ["hello","perfect2"];
// const res =  arr1.includesOneOf(arr2);
// console.log(res)

// const res1 =  arr4.includesOneOf(arr3);
// console.log(res1)

// // array  ??
// // object  ??
// const arrr3 = [[12,3,4] , [12,4,5]]
// const arrr4 = [[12,3,6] , [12,4,5] , [1,2,3]]

// // [[Protoype]]

// for ()
// forEach()
// while()
// map
// filter
// reduce

// for loop
// const mutliply = (array , i)=> {
//     array[i] = array[i]*2;
// }
// imperative approache

const array = [1, 2, 3, 4];
//  for(let  i=0 ;i<array.length;i*2+1) {
//    array[i]= array[i]*2;
//  }
const callBackFunc = (currElement, index, array) => {
  console.log(currElement, index, array);
};
array.forEach((currElement, index, orArray) => {
  orArray[index] = orArray[index] * 2;
  console.log(currElement, index, array);
});

// Map

const adda = () => {};
console.log("Heyy", adda());
const array1 = [3, 4, 5, 6, 7];
const callBackFuncMap = (element, index) => {
  return element * 2;
};

const array2 = array1.map(callBackFuncMap);

console.log(array2, array1);

Array.prototype.myMap = function (callbackFunc) {
  let newArray = [];
  for (let i = 0; i < this.length; i++) {
    const updatedElement = callbackFunc(this[i], i, this);
    newArray.push(updatedElement);
  }
  return newArray;
};
const array4 = [2, 3, 4, 5, 6, 7];
const checkCall = (elem, index, array) => {
  return {
    [index]: elem,
  };
};
const data1 = array4.myMap(checkCall);
const data2 = array4.map(checkCall);
console.log("data1", data1);
console.log(JSON.stringify(data1) === JSON.stringify(data2));

// filter own pollyfill

Array.prototype.myFilter = function (callbackFunc) {
  let newArray = [];
  for (let i = 0; i < this.length; i++) {
    const updatedElement = callbackFunc(this[i], i, this);
    if (updatedElement) {
      newArray.push(this[i]);
    }
  }
  return newArray;
};

Array.prototype.myMap = function (callbackFunc) {
  let newArray = [];
  for (let i = 0; i < this.length; i++) {
    const updatedElement = callbackFunc(this[i], i, this);
    newArray.push(this[i]);
  }
  return newArray;
};

const data123 = [4, 5, 6, 7, 8, 8, 8, 8, 9, 8, 8, 8];

let ans =
  Array.isArray(data123) &&
  data123.filter((ele) => {
    return ele < 8;
  });

// array reduce polyfill
const array5 = [3, 7, 9];
const callbackReduce = (prev, curr, index) => {
  if (curr % 2 == 0) {
    prev = curr;
  }
};

// call , bind , apply
// reduce
// questions
// prototype

// protoype
//  class

// async

// sat and sun

// polffill => map , filter  and reduce

// Reduce Polyfill

const totalSum = array1.reduce((prev, curr) => {
  prev = prev + curr;
  return prev;
}, 0);

Array.prototype.myReduce = function (callbackFunction, initial) {
  this.forEach((elem) => {
    initial =
      typeof initial !== "undefined" ? callbackFunction(initial, elem) : elem;
  });
  return initial;
};

// it is manadatory key in reduce as initial value

const sumArray = [3, 4, 5];
const sum = sumArray.myReduce((prev, curr) => {
  return prev + curr;
});

console.log("sum=> ", sum);

const sum2 = sumArray.reduce((prev, curr) => {
  return prev * curr;
}, 0);

console.log(sum2);

Array.prototype.myReduce1 = function (cb, initialValue) {
  let ans = initialValue || (this[0] ? this[0] : undefined);
  if (ans !== undefined) {
    for (let i = initialValue ? 0 : 1; i < this.length; i++) {
      ans = cb(ans, this[i], i, this);
    }
  }
  return ans;
};

const data = [].myReduce1((acc, value) => {
  return acc + value;
});

const data22 = [].reduce((acc, value) => {
  return acc + value;
});
console.log(data1);
console.log(data2);