exec 匹配执行 找到返回是的内容 

<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="utf-8">
    </head>
    <body>
       <script>
        var txt = "hello 1234567890 HELLO byebye";
  var regex =  new RegExp("hello","gi");
  //g 执行全局匹配
  //i 大小写不敏感
  //m 执行多行匹配
  //var output = regex.exec(txt) 匹配执行 找到返回是的内容

  while ((output = regex.exec(txt)) != null){
    document.write('第' + regex.lastIndex +  '位,找到' + output + '<br/>')
  }
       </script>
    </body>
</html>

 

posted @ 2017-10-05 17:15  xuanPhoto  阅读(125)  评论(0)    收藏  举报