Below is the code for Validating RadioButton List to to check if selected using JavaScript in .net application.
In this code, we use a jQuery selector $('#rdblList input[type=radio]:checked') to select all the radio buttons under the rdblList table that are checked. We then use the .length property to check if the selected radio buttons length is greater than zero. If the length is zero then we display an error message.
<%@ Page Language="VB" AutoEventWireup="false" CodeFile="Test.aspx.vb" Inherits="Test" ValidateRequest="false" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
<head runat="server">
<title>Validate Radio Button list</title>
<%@ Page Language="VB" AutoEventWireup="false" CodeFile="Test.aspx.vb" Inherits="Test" ValidateRequest="false" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
<head runat="server">
<title>Validate Radio Button list</title>
<script src="https://code.jquery.com/jquery-3.6.0.min.js"></script>
<script type="text/javascript">
function validate() {
if ($('#rdblList input[type=radio]:checked').length == 0) {
alert("Please select gender.");
return false;
}
}
</script>
</head>
<body style="margin: 0;">
<form id="frmHome" method="post" runat="server">
<table id="Table1" style="width: 100%" cellspacing="0" cellpadding="0" border="0">
<tr>
<td align="center" valign="top" style="width: 100%;">
<asp:RadioButtonList runat="server" id="rdblList">
<asp:ListItem>Male</asp:ListItem>
<asp:ListItem>Female</asp:ListItem>
</asp:RadioButtonList>
<br />
<br />
<asp:Button runat="server" ID="btnval" Text="Validate" OnClientClick="return validate();" />
</td>
</tr>
</table>
</form>
</body>
</html>
function validate() {
if ($('#rdblList input[type=radio]:checked').length == 0) {
alert("Please select gender.");
return false;
}
}
</script>
</head>
<body style="margin: 0;">
<form id="frmHome" method="post" runat="server">
<table id="Table1" style="width: 100%" cellspacing="0" cellpadding="0" border="0">
<tr>
<td align="center" valign="top" style="width: 100%;">
<asp:RadioButtonList runat="server" id="rdblList">
<asp:ListItem>Male</asp:ListItem>
<asp:ListItem>Female</asp:ListItem>
</asp:RadioButtonList>
<br />
<br />
<asp:Button runat="server" ID="btnval" Text="Validate" OnClientClick="return validate();" />
</td>
</tr>
</table>
</form>
</body>
</html>