php正则验证邮箱二个例子

$str = "yuju100@123.com";
$partern = "/^[A-Za-z0-9+_]+@[A-Za-z0-9]+.[a-z]{2,4}$/";
$result = preg_match($partern,$str,$arr);
print_r($result);

class isEmail{
   public function run($email){
      if(ereg("^([a-zA-Z0-9_-])+@([a-zA-Z0-9_-])+(.[a-zA-Z0-9_-])+",$email)){
         return true;
      }else{
         return false;
      }
   }
}

$isEmail=new isEmail;
if($isEmail->run("going")==false){
   echo "email is wrong";
}