ChayeORCode/filter,map.html at main · ShifaRabbani/ChayeORCode · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Filters map and reduce in JS</title>
</head>
<body>
    <script>
        const coding = [43,5,23,12,45,67,89,"Shfia"]
        // for each can not return a value ,like this
        const values=coding.forEach((item) =>{
            console.log(item);
            return item;
        })
        console.log(values);


        const myNums=[1,2,3,4,5,6,7,8,9,10]
        // const newNum = myNums.filter( (num) => num > 4 )   //cal back function = (num) => num > 4 )
       // or  (if we are using a { } we must be used a keyword return )
       const newNum = myNums.filter((num) => {
        return num > 4 ;
       })
        console.log(newNum);


        const MyNums =[ 11,12,13,14,15,16,17,18,19,20]

        const newnum = []
        MyNums.forEach((num ) => {
          if (num > 14) {
            newnum.push(num)
          }
        })
        console.log(newnum);

           //************this is how  a filter actually works *****************
        const Books =[
            {title: 'Book one' , genre: 'Fiction' , publish: 1981 , edition:2004},
            {title: 'Book two' , genre: 'Non Fiction' , publish: 1990 , edition:2009},
            {title: 'Book three' , genre: 'History' , publish: 1931 , edition:2000},
            {title: 'Book four' , genre: 'Science' , publish: 1921 , edition:2009},
            {title: 'Book five' , genre: 'Litrature' , publish: 1981 , edition:2005},
            {title: 'Book six' , genre: 'Fiction' , publish: 1931 , edition:2007},
        ];
        let userBook = Books.filter((bk) => bk.genre === 'History' )
        userBook= Books.filter((bk) => {
            return bk.publish >= 1981  && bk.genre ==="Fiction"
        })
        console.log(userBook);


        // **********************Map function*****************
        const myNumbers = [11,22,33,44,55,66,77,88,99,110]

         const newNumbers=myNumbers.map( (num) => num + 5)
             console.log(newNumbers);

// OR
            const Newnums = []
           myNumbers.forEach((num) =>{
        num + 10
        Newnums.push(num)
           });
          console.log(Newnums);

        //    ****************************chaining*********************
         const number = [1,2,3,4,5,6,7,8,9,10]
         const newnumber = number
                           .map((num) => num *10)
                           .map((num) => num -1)
                           .map((num) => num +2)
                           .filter((num) => num >= 40)   //filter is used for true fal se
                console.log(newnumber);

                // ***************************** reduce ****************

const myNum = [1,2,3,4,5]
// const myTotal = myNum.reduce(function (accumulaotr, currentValue){            //accumulator is a variabe that store a current value
// console.log(`accumulator:${accumulaotr} and  current value:${currentValue}`);


// return accumulaotr + currentValue;
// } ,0 )                       //0 here we declare that accumulator initial value is 0 , and then accumulator store the currentvalue

//  ************************* from a arrow function
const myTotal =myNum.reduce(( accumulaotr , currentValue) => accumulaotr + currentValue ,0)


console.log(`myTotal amount  is : ${myTotal}`);

//       **************************Shopping cart *****************

const ShoppingCart =[
    {
        itemName : "Js course ",
        price : 2900
    },
     {
        itemName : "py course ",
        price : 3000
    },
     {
        itemName : "app dev curse ",
        price : 5000
    },
     {
        itemName : "c++ course",
        price : 1500
    },
];
const priceToPay = ShoppingCart.reduce( (acc ,item ) => acc + item.price, 0);

console.log(priceToPay);


    </script>
</body>
</html>