正则的使用方法

一 javascript正则表达式的基本知识 

1     javascript 正则对象创建 和用法 

    声明javascript 正则表达式 
   
     var reCat = new RegExp("cat"); 
      你也可以 
     var reCat = /cat/;      //Perl 风格   （推荐） 

2 学习最常用的 test exec match search  replace  split 6个方法 

   1） test  检查指定的字符串是否存在 

       var data = "123123"; 
       var reCat = /123/gi; 
       alert(reCat.test(data));  //true 
     
       //检查字符是否存在  g 继续往下走  i 不区分大小写 

   2） exec 返回查询值 

       var data = "123123,213,12312,312,3,Cat,cat,dsfsdfs,"; 
       var reCat = /cat/i; 
       alert(reCat.exec(data));  //Cat 

     3）match  得到查询数组 

       var data = "123123,213,12312,312,3,Cat,cat,dsfsdfs,"; 
       var reCat = /cat/gi; 
       var arrMactches = data.match(reCat) 

       for (var i=0;i < arrMactches.length ; i++) 
       { 
            alert(arrMactches);   //Cat  cat 
       } 

     4） search  返回搜索位置  类似于indexof 

       var data = "123123,213,12312,312,3,Cat,cat,dsfsdfs,"; 
       var reCat = /cat/gi; 
       alert(data.search(reCat));  //23 


    5） replace  替换字符  利用正则替换 

       var data = "123123,213,12312,312,3,Cat,cat,dsfsdfs,"; 
       var reCat = /cat/gi; 
       alert(data.replace(reCat,"libinqq")); 

    6）split   利用正则分割数组 

       var data = "123123,213,12312,312,3,Cat,cat,dsfsdfs,"; 
       var reCat = /\,/; 
       var arrdata = data.split(reCat); 

       for (var i = 0; i < arrdata.length; i++) 
       { 
            alert(arrdata); 
       } 

3  学习下  简单类   负向类  范围类  组合类 

    //简单类 
       var data = "1libinqq,2libinqq,3libinqq,4libinqq"; 
       var reCat = /[123]libinqq/gi; 
       var arrdata = data.match(reCat); 

       for (var i = 0; i < arrdata.length; i++) 
       { 
            alert(arrdata);  // 1libinqq 2libinqq  3libinqq 
       } 

       //负向类 
       var data = "alibinqq,1libinqq,2libinqq,3libinqq,4libinqq";  //u0062cf 
       var reCat = /[^a123]libinqq/gi; 
       var arrdata = data.match(reCat); 

       for (var i = 0; i < arrdata.length; i++) 
       { 
            alert(arrdata);  //4libinqq 
       } 

       //范围类 
       var data = "libinqq1,libinqq2,libinqq3,libinqq4,libinqq5";  //u0062cf 
       var reCat = /libinqq[2-3]/gi; 
       var arrdata = data.match(reCat); 

       for (var i = 0; i < arrdata.length; i++) 
       { 
            alert(arrdata);   // libinqq2  libinqq3 
       } 

       //组合类 
      var data = "a,b,c,w,1,2,3,5";  //u0062cf 
       var reCat = /[a-q1-4 ]/gi; 
       var arrdata = data.match(reCat); 

       for (var i = 0; i < arrdata.length; i++) 
       { 
            alert(arrdata);  // a b c 1 2 3 
       } 
二  javascript  正则表达式是分组知识 
1） 简单分组 

1.     <script language="JavaScript">   
   
2.       <!--   
3.              
4.            
5.         var data = "Ah-mousemouse";     
6.         var reCat = /(mouse){2}/gi;      
7.         var arrdata = data.match(reCat);   
8.       
9.         for (var i = 0; i < arrdata.length; i++)   
10.         {   
11.             alert(arrdata[i]);   
12.         }   
13.       //-->   
14.       </script>  

复制代码

2 复杂分组

1.     <script language="JavaScript">   
2.       <!--   
3.              
4.            
5.         var data = "bb ba da bad dad aa ";     
6.         var reCat = /([bd]ad?)/gi;   // 匹配出 ba da bad  dad   
7.         var arrdata = data.match(reCat);   
8.       
9.         for (var i = 0; i < arrdata.length; i++)   
10.         {   
11.             alert(arrdata[i]);   
12.         }       
13.            
14.       
15.         // 同时 也不介意将分组放在分组中间   
16.         // var re = /(mom( and dad)?)/;    匹配出 mom  或  mon and daa   
17.       //-->   
18.       </script>  

复制代码

3 反向引用

1.     <script language="JavaScript">   
2.       <!--   
3.           
4.       
5.         var sToMatch = "#123456789";   
6.         var reNumbers = /#(d+)/;   
7.         reNumbers.test(sToMatch);   
8.         alert(RegExp.$1);   
9.       
10.           
11.       
12.       
13.         var sToChange = "1234 5678";   
14.         var reMatch = /(d{4}) (d{4})/;   
15.         var sNew = sToChange.replace(reMatch,"$2 $1");   
16.         alert(sNew);   
17.       
18.           
19.       
20.       //-->   
21.       </script>  

复制代码

4 候选

1.     <script language="JavaScript">   
2.       <!--   
3.           
4.         var sToMatch1 = "red";   
5.         var sToMatch2 = "black";   
6.         var reRed = /red/;   
7.         var reBlack = /black/;   
8.       
9.         alert(reRed.test(sToMatch1) || reBlack.test(sToMatch1));   
10.         alert(reRed.test(sToMatch2) || reBlack.test(sToMatch2));   
11.       
12.           
13.       
14.         var sToMatch1 = "red";   
15.         var sToMatch2 = "black";   
16.         var reRedOrBlack = /(red|black)/;   
17.         alert(reRedOrBlack.test(sToMatch1));   
18.         alert(reRedOrBlack.test(sToMatch2));   
19.       
20.       //-->   
21.       </script>  

复制代码

5 非捕获性分组

1.     <script language="JavaScript">   
2.       <!--   
3.           
4.       
5.         var sToMatch = "#123456789";   
6.         var reNumbers = /#(?:d+)/;   
7.         reNumbers.test(sToMatch);   
8.         alert(RegExp.$1);   
9.       
10.           
11.       
12.         var sToMatch = "#123456789";   
13.         var reNumbers = /#(?:d+)/;   
14.         alert(sToMatch.replace(reNumbers,"abcd$1"));   
15.       
16.           
17.       //-->   
18.       </script>  

复制代码

6 前瞻

1.     <script language="JavaScript">   
2.       <!--   
3.           
4.       
5.       
6.           var sToMatch1 = "bedroom";   
7.           var sToMatch2 = "bedding";   
8.           var reBed = /bed(?=room)/;    
9.           alert(reBed.test(sToMatch1));  //true   
10.           alert(reBed.test(sToMatch2));  //false   
11.           
12.         //负向前瞻   
13.            
14.           var sToMatch1 = "bedroom";   
15.           var sToMatch2 = "bedding";   
16.           var reBed = /bed(?!room)/;    
17.           alert(reBed.test(sToMatch1)); //false   
18.           alert(reBed.test(sToMatch2)); //true   
19.       //-->   
20.       </script>  

复制代码

7 边界

1.     <script language="JavaScript">   
2.       <!--   
3.           
4.       
5.           var sToMatch = "Important word is the last one.";   
6.           var reLastWord = /(w+).$/;    
7.           reLastWord.test(sToMatch);   
8.           alert(RegExp.$1);  //one   
9.       
10.           
11.       
12.       
13.       
14.           var sToMatch = "Important word is the last one.";   
15.           var reLastWord = /^(w+)/;    
16.           reLastWord.test(sToMatch);   
17.           alert(RegExp.$1);  //Important   
18.       
19.           
20.           
21.           var sToMatch = "Important word is the last one.";   
22.           var reLastWord = /^(.+?)/;    
23.           reLastWord.test(sToMatch);   
24.           alert(RegExp.$1);  //Important   
25.            
26.           
27.       
28.         var data = " First second thind fourth fifth sixth ";     
29.         var reCat = /(S+?)/g;      
30.         var arrdata = data.match(reCat);   
31.       
32.         for (var i = 0; i < arrdata.length; i++)   
33.         {   
34.             alert(arrdata[i]);   
35.         }      
36.       
37.           
38.       //-->   
39.       </script>  

复制代码

8 多行模式

1.     <script language="JavaScript">   
2.       <!--   
3.              
4.            
5.         var data = " First second thind fourth fifth sixth";     
6.         var reCat = /(w+)$/g;      
7.         var arrdata = data.match(reCat);   
8.       
9.         for (var i = 0; i < arrdata.length; i++)   
10.         {   
11.             alert(arrdata[i]);   
12.         }     
13.            
14.              
15.         var data = " First second thind fourth fifth sixth";     
16.         var reCat = /(w+)$/gm;      
17.         var arrdata = data.match(reCat);   
18.       
19.         for (var i = 0; i < arrdata.length; i++)   
20.       
21.         {   
22.             alert(arrdata[i]);   
23.         }  a   
24.            
25.       
26.       //-->   
27.       </script>  

复制代码

转载出处:http://www.ok22.org/art_detail.aspx?id=209【js的正则方法使用实例】幸凡在线学习网