加减 script函数初识

 1 <!DOCTYPE html>
 2 <html lang="en">
 3 <head>
 4     <meta charset="UTF-8">
 5     <title>Title</title>
 6     <style>
 7         body{
 8             margin: 0;
 9         }
10         .c1{
11             top: 10px;
12             left: 10px;
13             position: relative;
14             width: 150px;
15             height: 22px;
16             border: 1px solid black;
17             padding-right: -22px;
18         }
19         .c2{
20             position: absolute;
21             width: 22px;
22             height: 22px;
23 
24             line-height: 22px;
25             text-align: center;
26             background-color: #dce7f4;
27             border-right: 1px solid black;
28             cursor: pointer;
29         }
30         .c3{
31 
32         }
33         .c3 input{
34             border: 0;
35             padding: 0;
36             position: absolute;
37             left: 23px;
38             width: 104px;
39             height: 22px;
40             line-height: 22px;
41             text-align: center;
42 
43 
44         }
45 
46         .c4{
47             right: 0;
48             position: absolute;
49             width: 22px;
50             height: 22px;
51             line-height: 22px;
52             text-align: center;
53             border-left: 1px solid black;
54             background-color: #dce7f4;
55             cursor: pointer;
56         }
57 
58     </style>
59 </head>
60 <body>
61     <div class="c1">
62         <div class="c2" onclick="Minus()">-</div>
63 
64          <div class="c3">
65             <input type="text" id="count" value="0" />
66         </div>
67 
68         <div class="c4"  onclick="Plus()">+</div>
69     </div>
70     <script type="text/javascript">
71         //定义函数
72         function Plus() {
73             var old_str = document.getElementById('count').value;
74             try{
75                 var old_int = parseInt(old_str);
76             }catch(e){
77                 var old_int = 1
78             }
79             var new_int = old_int + 1;
80             document.getElementById('count').value = new_int;
81         }
82         function Minus() {
83             var old_str = document.getElementById('count').value;
84             try{
85                 var old_int = parseInt(old_str);
86             }catch(e){
87                 var old_int = 1
88             }
89             var new_int = old_int - 1;
90             document.getElementById('count').value = new_int;
91         }
92     </script>
93 </body>
94 </html>

 

posted @ 2017-03-06 20:35  失落的黎明  阅读(230)  评论(0编辑  收藏  举报