代码改变世界

36.数组去重

2017-06-05 16:35  笨笨03  阅读(202)  评论(0)    收藏  举报 
 1 <!DOCTYPE html>
 2 <html>
 3 <head lang="en">
 4     <meta charset="UTF-8">
 5     <title>数组去重</title>
 6 
 7 </head>
 8 <body>
 9 </body>
10 <script type="text/javascript">
11 
12     var strs = ['a', 'a', 5, 5,7];
13 
14     function remove1(str) {
15         var newStr = [], obj = {};
16         for (var i = 0, h = str.length; i < h; i++) {
17             if (!obj[str[i]]) {
18                 newStr.push(str[i]);
19                 obj[str[i]] = 1;
20             }
21         }
22         return newStr;
23     }
24     var s1 = remove1(strs);
25     console.log('s1:' + s1);
26 
27 
28     function remove2(str) {
29         return Array.from(new Set(str));
30     }
31 
32     var s2 = remove2(strs);
33     console.log('s2:' + s2)
34 
35 
36     function remove3(str) {
37         var newStr = [];
38         for (var i = 0, j = str.length; i < j; i++) {
39             if (newStr.indexOf(str[i]) === -1) {
40                 newStr.push(str[i]);
41             }
42         }
43         return newStr;
44     }
45     var s3=remove3(strs);
46     console.log('s3:'+s3);
47 
48     //4
49     function remove4(str) {
50         var newStr = [];
51 
52         str.forEach(function(e, i, str) {
53             if (str.indexOf(e) === i) {
54                 newStr.push(e);
55             }
56         });
57 
58         return newStr;
59     }
60 
61     var s4=remove4(strs);
62     console.log('s4:'+s4);
63 
64     //5
65     function remove5(str) {
66         var newStr = [],
67                end;
68         str.sort();
69         end = str[0];
70         newStr.push(str[0]);
71 
72         for (var i = 1; i < str.length; i++) {
73             if (str[i] != end) {
74                 newStr.push(str[i]);
75                 end = str[i];
76             }
77         }
78         return newStr;
79     }
80 
81     var s5=remove5(strs);
82     console.log('s5:'+s5);
83 
84 
85 
86 </script>
87 
88 </html>
View Code

效果图：

<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title>数组去重</title>

</head>
<body>
</body>
<script type="text/javascript">

    var strs = ['a', 'a', 5, 5,7];

    function remove1(str) {
        var newStr = [], obj = {};
        for (var i = 0, h = str.length; i < h; i++) {
            if (!obj[str[i]]) {
                newStr.push(str[i]);
                obj[str[i]] = 1;
            }
        }
        return newStr;
    }
    var s1 = remove1(strs);
    console.log('s1:' + s1);


    function remove2(str) {
        return Array.from(new Set(str));
    }

    var s2 = remove2(strs);
    console.log('s2:' + s2)


    function remove3(str) {
        var newStr = [];
        for (var i = 0, j = str.length; i < j; i++) {
            if (newStr.indexOf(str[i]) === -1) {
                newStr.push(str[i]);
            }
        }
        return newStr;
    }
    var s3=remove3(strs);
    console.log('s3:'+s3);

    //4
    function remove4(str) {
        var newStr = [];

        str.forEach(function(e, i, str) {//固定顺序，e是数组元素，i是数组元素下标
            if (str.indexOf(e) === i) {
                newStr.push(e);
            }
        });

        return newStr;
    }

    var s4=remove4(strs);
    console.log('s4:'+s4);

    //5
    function remove5(str) {
        var newStr = [],
               end;
        str.sort();
        end = str[0];
        newStr.push(str[0]);

        for (var i = 1; i < str.length; i++) {
            if (str[i] != end) {
                newStr.push(str[i]);
                end = str[i];
            }
        }
        return newStr;
    }

    var s5=remove5(strs);
    console.log('s5:'+s5);



</script>

</html>