使用javascript验证表单字段的空电子邮件输入

Question

Html :

<input style="margin-top: 20px;" type="text" placeholder="Enter an Email ID" name="Email" id="Email" pattern="((\w+\.)*\w+)@(\w+\.)+(com|kr|net|us|info|biz)" required="required">

Script :

<script type="text/javascript">
    function checkStatus() {
        var productcode = $("#Code").val();
        var productEmail = $("#Email").val();
        alert("email is== " + Email)

        if (!document.getElementById("Email").checkValidity()) {
            alert("Please Enter Valid Email Id");
            return false;

        } else {
            callMeIfValid();
        }

        document.getElementById('Email').value = '';    
    }

    function callMeIfValid() {    
        alert("valid input");    
    }
</script>

In the above code i am able to validate whether the email id given by user is valid or not based on the regex pattern inside input tag.But i Want to perform validation when the user submits an empty field( without any email input ). Is there any possibility?any help would be appreciated..

Answer 1

您可以首先使用 .val() 检查用户是否输入了任何文本或值，然后检查输入是否有效。

Answer 2

Use this

JS

if(document.getElementById("Email").value=='')
{
  alert("Please Enter Email ID");
  return false;    
}

DEMO

Note: HTML5 required attribute may not work on all browsers.

Answer 3

where there is your < form > tag in html add this attribute

example:

<form onsubmit="return validate();" bla bla bla>  // put onsubmit in your form tag

and then write this jquery function

function validate(){
    if($("#Email").val()=='')
    {
        alert("Please Enter Email ID");
        return false;    
    }
 }