To select a radio button by default we have to check it as true. If it is checked as true then by default it will be autofocused.
In the following example, we have only radio buttons and none of them is autofocused.
Example
<html> <form id="radiobuttons" name="radiobutton"> <input id="rad1" value="a" type="radio" name="check"/>male <input id="rad2" value="b" type="radio" name="check"/>female <input id="rad3" value="c" type="radio" name="check"/>other </form> <body> </body> </html>
When the above code is executed we will get radio buttons and none of them is autofocused as shown in the following image.
Output
To autofocus any of the above buttons we have to check them initially. This can be done by using pure javascript as shown in the following example.
Example
<html>
<form id="radiobuttons" name="radiobutton">
<input id="rad1" value="a" type="radio" name="check"/>male
<input id="rad2" value="b" type="radio" name="check"/>female
<input id="rad3" value="c" type="radio" name="check"/>other
</form>
<body>
<script>
radiobtn = document.getElementById("rad1");
radiobtn.checked = true;
</script>
</body>
</html>After executing the above code, we will get the following output.
Output
