求一段判断字符串是否是邮箱格式的代码

Question

各位大哥请用代码砸我把

Answer 1

正则表达式 "w+([-+.]w+)*@w+([-.]w+)*.w+([-.]w+)*"

Answer 2

一般都是先用javascript做前台判断，前台判断为
<script language="JavaScript">
<!--
function chk(theform)
{
 if(theform.email.value.length!=0)
  {
    if (theform.email.value.charAt(0)=="." ||        
        theform.email.value.charAt(0)=="@"||       
         theform.email.value.indexOf('@', 0) == -1 || 
         theform.email.value.indexOf('.', 0) == -1 || 
         theform.email.value.lastIndexOf("@")==theform.email.value.length-1 || 
         theform.email.value.lastIndexOf(".")==theform.email.value.length-1)
     {
      alert("Email地址格式不正确！");
      theform.email.focus();
      return false;
      }
   }
 else
  {
   alert("Email不能为空！");
   theform.email.focus();
   return false;
   }}
//-->
</script>