<input type="text" placeholder="请输入邮箱" id="email"> <script> email.onchange = function(){ var email = this.value; var reg = /^([a-zA-Z]|[0-9])(\w|\-)[email protected][a-zA-Z0-9]+\.([a-zA-Z]{2,4})$/; if(reg.test(email)){ alert("邮箱格局正确"); }else{ alert("邮箱格局不正确"); } } </script> </html>

邮箱验证-JS正则表达式