html - Javascript value of a single radio button

Question

I have a form that can have a varible number of radio buttons. From one to sixteen. I have a switch statement where I want various actions to happen if the user presses a certian button. If they press the number one on the numberic keypad, I want the first radio button to be selected and the form to be submitted.

case 97:
                            document.form_name.radio[0].checked=true;
                            document.form_name.submit();
                            break;

This works when there is more than one radio button in the form but when there is only one, it doesn't work. I can find out before I execute to code how many radio buttons are in the form. What code to I need to use the check the radio button, if it is the only one?

Answer 1

You can use querySelector since it only selects the FIRST anyway. You can also use querySelectorAll and the position in the array to select any other radios also.

document.querySelector("input[name='drop_items']").checked=true;
//document.querySelectorAll("input[name='drop_items']")[1].checked=true;

<input type="radio" name="drop_items" value="1">
<input type="radio" name="drop_items" value="12">