js正则表达式验证

1 <h3>绿色表示匹配，红色表示不匹配</h3>
2 <label>请在下框填入正则表达式</label><br />
3 
4 <textarea id="regexp"></textarea><br />
5 
6 <label>请在下框填需要验证的式子</label><br />
7 
8 <textarea id="needtest"></textarea>

1 #regexp,#needtest { height:100px; width:300px; resize:none; font-weight:bold;}

 1 window.onload = function(){
 2     
 3     
 4     
 5     document.getElementById(‘needtest‘).onkeyup = function(){
 6         var ret = document.getElementById(‘regexp‘).value;
 7         ret = ‘^‘ + ret + ‘$‘;
 8         var re = new RegExp(ret)
 9         
10         if(re.test(document.getElementById(‘needtest‘).value)){
11             
12             document.getElementById(‘needtest‘).style.color = ‘green‘;
13         }else{
14             document.getElementById(‘needtest‘).style.color = ‘red‘;
15         }
16     }
17     
18     document.getElementById(‘regexp‘).onkeyup = function(){
19         var ret = document.getElementById(‘regexp‘).value;
20         ret = ‘^‘ + ret + ‘$‘;
21         var re = new RegExp(ret)
22         
23         if(re.test(document.getElementById(‘needtest‘).value)){
24             
25             document.getElementById(‘needtest‘).style.color = ‘green‘;
26         }else{
27             document.getElementById(‘needtest‘).style.color = ‘red‘;
28         }
29     }
30     
31 }