javascript数组笔记

 1  // 打印出星期日
 2     var newArr = ["星期一", "星期二", "星期三", "星期四", "星期五", "星期六", "星期日"]
 3     console.log(newArr[6]);
 4     // 遍历出数组内容
 5     for (var i = 0; i < newArr.length; i++) {
 6         console.log(newArr[i]);
 7     }
 8 
 9     // 求数组中的和,平均值
10     var num = [2, 6, 1, 7, 4]
11     var sum = 0
12     for (var j = 0; j < num.length; j++) {
13         sum += num[j]
14     }
15     var average = sum / 5
16     console.log(sum, average);
17 
18 
19     // 求数组中最大值
20     var points = [40, 600, 1, 45, 68, 44]
21     // 方法一
22     var max = points[0]
23     for (var a = 1; a < points.length; a++) {
24         if (points[a] > max) {
25             max = points[a]
26         }
27     }
28     console.log(max);
29 
30     // 方法二
31     points.sort(function (a, b) {
32         return b - a
33     });
34     var list = points[0]
35     console.log(list);
36 
37 
38     // 数组转换字符串
39     var arr = [‘red‘, ‘jjj‘, ‘iii‘]
40     var str = ‘‘
41     var edg = ‘----------‘
42     for (var t = 0; t < arr.length; t++) {
43         str += arr[t] + edg
44     }
45     console.log(str);
46 
47     // 修改length长度增加元素
48     var dataArr = [‘2012‘, ‘2015‘, ‘1033‘]
49     dataArr.length = 5
50     console.log(dataArr.length);
51 
52     // 修改索引号追加数字元素
53     dataArr[3] = ‘3333‘
54     console.log(dataArr);
55 
56 
57     // 将1~10存放到数组里面
58     var list = []
59     for (var d = 1; d <= 10; d++) {
60         list.push(d)
61     }
62     console.log(list);
63 
64 
65     // 遍历出数组中大于10的数字
66     var numlist = [2, 5, 88, 44, 65, 57, 95, 4, 55, 6]
67     var lists = []
68     for (var s = 0; s < numlist.length; s++) {
69         if (numlist[s] > 10) {
70             lists.push(numlist[s])
71         }
72     }
73     console.log(lists);
74 
75 
76     // 数组删除指定数据
77     var numberArr = [0, 99, 3, 4, 0, 65]
78     var newNumArr = []
79     var newArr2 = []
80     for (var e = 0; e < numberArr.length; e++) {
81         if (numberArr[e] != 0) {
82             // 方法一
83             newNumArr.push(numberArr[e])
84             // 方法二
85             // newNumArr[newNumArr.length] = numberArr[e]
86         }
87     }
88     console.log(newNumArr);
89 
90     // 将数组翻转
91     for (var c = newNumArr.length - 1; c >= 0; c--) {
92         newArr2.push(newNumArr[c])
93     }
94     console.log(newArr2);

 1     // 冒泡排序
 2     var arr = [5, 3, 4, 2, 1]
 3     for (var i = 0; i <= arr.length - 1; i++) { //循环次数
 4         for (var j = 0; j <= arr.length - i - 1; j++) { //循环每一次交换的次数
 5             if (arr[j] > arr[j + 1]) {
 6                 var temp = arr[j]
 7                 arr[j] = arr[j + 1]
 8                 arr[j + 1] = temp
 9             }
10         }
11     }
12     console.log(arr);