RadioButton

A radio button in an HTML form is used to allow a user to make a single selection from a list of mutually exclusive options. It is represented by the <input type="radio"> element.

Here is an example of an HTML form with radio buttons:

<form>
 <label for="gender_male">Male</label>
 <input type="radio" id="gender_male" name="gender" value="male">
 <label for="gender_female">Female</label>
 <input type="radio" id="gender_female" name="gender" value="female">
 <label for="gender_other">Other</label>
 <input type="radio" id="gender_other" name="gender" value="other">
 <input type="submit" value="Submit">
</form>

In this example, the form has three radio buttons with the labels "Male", "Female", and "Other". Each radio button is represented by an <input> element with the type attribute set to "radio". The id attribute is used to associate the radio button with its corresponding label, and the name attribute is used to group the radio buttons together so that only one can be selected at a time. The value attribute is used to identify the selected option when the form is submitted.

Also, you can make a radio button pre-selected by adding checked attribute to the desired radio button element.

<input type="radio" id="gender_male" name="gender" value="male" checked>