js regex正則tricks

  
    

   
      
   
     <
   
     script type
   
     =
   
     "
   
     text/javascript
   
     "
   
     >
   
     
 
   
     <!--
   
     
 
   
     function
   
      MatchDemo(){
 
   
     var
   
      r, re; 
   
     //
   
          。
   
     

   
      
   
     var
   
      s 
   
     =
   
      
   
     "
   
     The123 rain in Spain falls mainly in the plain
   
     "
   
     ;
 re 
   
     =
   
      
   
     /
   
     ain
   
     /
   
     ig; 
   
     //
   
               。
   
     

   
      r 
   
     =
   
      s.match(re); 
   
     //
   
                。
   
     

   
      
   
     //
   
     debugger;
   
     

   
      
   
     //
   
     return(r); //            "ain" 
   
     

   
      
   
     //
   
             。
   
     

   
     

   
     //
   
     ////////////////////////////////////
   
     

   
      
   
     var
   
      regex
   
     =
   
     /
   
     ((T\w*)e)(\d*)
   
     /
   
     ;
 
   
     var
   
      matches
   
     =
   
      regex.exec(s);
 
   
     debugger
   
     ;
 
   
     /*
   
     
  :matches ["The123", "The", "Th", "123"] 
0 "The123" 
1 "The" 
2 "Th" 
3 "123" 
index 0 
input "The123 rain in Spain falls mainly in the plain"
 
   
     */
   
     
}
 
   
     //
   
     -->
   
     

   
      
   
     <
   
     /
   
     script>