In this article, I will show you to check blank white space using trim in jQuery example. You can check the user input blank white space in a client side click.
JQuery example:
<script type="text/javascript" src="//code.jquery.com/jquery-1.10.2.js"></script>
<script type="text/javascript">
$(document).ready(function () {
$('#btnSubmit').click(function () {
if ($.trim($('#txtName').val()) == '')
alert('input is blank');
});
});
</script>
<input type="text" id="txtName" placeholder="please entername" />
<input id="btnSubmit" type="submit" value="Submit" />
Output: