JSFiddle - React, Tailwind, and code Playground

HTML

<input type="radio" name="elemainfoto" value="1" />
    <input type="radio" name="elemainfoto" value="2" />
    <input type="radio" name="elemainfoto" value="3" />
    <input type="submit" onclick="doCheck()" />

JavaScript

var radio = document.getElementsByName('elementinfoto'); console.log(radio); // get all radio buttons
     var isChecked = 0; // default is 0 
     for(var i=0; i<radio.length;i++) { // go over all the radio buttons with name 'elementinfoto'
       if(radio[i].checked) isChecked = 1; // if one of them is checked - tell me
     }
    
   //  if(isChecked == 0) // if the default value stayed the same, check the first radio button
      // radio[0].checked = "checked";