JS里的居民们8-对象和数组转换

Posted 2021-01-25 JoeJoan

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编码

学习通用的数据用不同的数据结构进行存储，以及相互的转换

对象转为数组：

var scoreObject = {
    "Tony": {
        "Math": 95,
        "English": 79,
        "Music": 68
    }, 
    "Simon": {
        "Math": 100,
        "English": 95,
        "Music": 98
    }, 
    "Annie": {
        "Math": 54,
        "English": 65,
        "Music": 88
    }
}

如上有一个用来存储学习成绩的对象，编写一个函数，将其转为如下的二维数组

var scoreArray = [
    ["Tony", 95, 79, 68],
    ……
];

数组转为对象：

var menuArr = [
    [1, "Area1", -1],
    [2, "Area2", -1],
    [3, "Area1-1", 1],
    [4, "Area1-2", 1],
    [5, "Area2-1", 2],
    [6, "Area2-2", 2],
    [7, "Area1-2-3", 4],
    [8, "Area2-2-1", 6],
];

如上有一个用来存储多级菜单数据的数组，编写一个函数，将其转为如下的对象

var menuObject = {
    "1": {
        name: "Area1",
        subMenu: {
            "3": {
                name: "Area1-1"
            },
            "4": {
                name: "Area1-2",
                subMenu: {
                    "7": {
                        name: "Area1-2-3"
                    }
                }
            }
        }
    }

    ……

}

 1 <!DOCTYPE html>
 2 <html>
 3 
 4 <head>
 5     <meta charset="utf-8" />
 6     <title>JS里的居民们9-对象和数组转换</title>
 7 </head>
 8 
 9 <body>
10     <script>
11         //对象转数组
12         var scoreObject = {
13             "Tony": {
14                 "Math": 95,
15                 "English": 79,
16                 "Music": 68
17             },
18             "Simon": {
19                 "Math": 100,
20                 "English": 95,
21                 "Music": 98
22             },
23             "Annie": {
24                 "Math": 54,
25                 "English": 65,
26                 "Music": 88
27             }
28         }
29         var arr1 = [];
30         for (var i in scoreObject) {
31             var arr2 = [];
32             arr2.push(i);
33             for (var j in scoreObject[i]) {
34                 arr2.push(scoreObject[i][j]);
35             }
36             arr1.push(arr2);
37         }
38         console.log(arr1);
39         //数组转对象
40         var menuArr = [
41             [1, "Area1", -1],
42             [2, "Area2", -1],
43             [3, "Area1-1", 1],
44             [4, "Area1-2", 1],
45             [5, "Area2-1", 2],
46             [6, "Area2-2", 2],
47             [7, "Area1-2-3", 4],
48             [8, "Area2-2-1", 6],
49         ];
50 
51         var menuObject = {};
52         menuArr.forEach((current, index) => {
53             if (current[2] == -1) {
54                 menuObject[current[0]] = {
55                     "name": current[1],
56                     "subMenu": {}
57                 }
58             }
59             if (current[2] == 1) {
60                 menuObject["1"]["subMenu"][current[0]] = {
61                     "name": current[1],
62                     "subMenu": {}
63                 }
64             }
65             if (current[2] == 2) {
66                 menuObject["2"]["subMenu"][current[0]] = {
67                     "name": current[1],
68                     "subMenu": {}
69                 }
70             }
71             if (current[2] == 4) {
72                 menuObject["1"]["subMenu"]["4"]["subMenu"][current[0]] = {
73                     "name": current[1],
74                     "subMenu": {}
75                 }
76             }
77             if (current[2] == 6) {
78                 menuObject["2"][ "subMenu"]["6"]["subMenu"][current[0]] = {
79                     "name": current[1],
80                     "subMenu": {}
81                 }
82             }
83         })
84         console.log(menuObject);
85     </script>
86 </body>
87 
88 </html>

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