required attribute for radio type inputs code example
Example 1: radio button required
One input with required attribute is enough.
<form>
Select Gender:
<label><input type="radio" name="gender" value="male" required>Male</label>
<label><input type="radio" name="gender" value="female">Female</label>
<label><input type="radio" name="gender" value="other">Other</label>
<input type="submit">
</form>
Example 2: how to put required in radio button
<form method="post" action="/Tests/Post" onsubmit="return ValidateForm();"> <fieldset> <legend>What is Your Favorite Pet?</legend> <input type="radio" name="favorite_pet" value="Cats" checked>Cats<br> <input type="radio" name="favorite_pet" value="Dogs">Dogs<br> <input type="radio" name="favorite_pet" value="Birds">Birds<br> <br> <input type="submit" value="Submit now"> </fieldset></form><script type="text/javascript">function ValidateForm(){ var radioButtons = document.getElementsByName("favorite_pet"); for(var i = 0; i < radioButtons.length; i++) { if(radioButtons[i].checked == true) { if(confirm("You have selected " + radioButtons[i].value + " as your favorite pet. Is that correct?")) return true; else return false; } }}</script>