保存状态单选按钮javascript-html

Question

I´m trying to do a program that save the state of the radio button and check it. This is my code but I don´t know what it`s wrong. Help me please

<script>
function saveState(){
   var ans1 = document.getElementById('grupo1');
   if (ans1.value == 1)
   {
       ans1.setAttribute("checked","checked");
       ans1.checked = true;
   }
</script>

<input type="radio" name="group" id="grupo1" value="1"> One
<input type="radio" name="group" id="grupo2" value="0"> Two
<input type="submit" onclick="saveState()" value="update">

Answer 1

Try this:

<script>
    function saveState(){
        var ans1 = document.querySelector('input[name="group"]:checked').value;

        if (ans1.value == 1){
              ans1.setAttribute("checked","checked");
              ans1.checked = true;
        }
   }
  </script>

Answer 2

You perhaps mean this?

You code does not make much sense unless the grupo1 button can change value

The following script assumes you have a standard cookie script somewhere

<script>
window.onload=function() {
  if (getCookie("grupo1")=="true") {
   document.getElementById('grupo1').click(); 
  }
  // either this
  document.getElementById('grupo1').onclick=function() {
     setCookie("grupo1","true")
  }
  // or this - depending on when you want to save the state
  document.getElementById("form1").onsubmit=function() {
    setCookie("grupo1",document.getElementById('grupo1').checked?"true":"false");
  }
}
</script>
<form id="form1">
<input type="radio" name="group" id="grupo1" value="1"> One
<input type="radio" name="group" id="grupo2" value="0"> Two
<input type="submit" value="update">
</form>

Answer 3

Being consequent in your approach towards placing brackets helps preventing situations like thisone.

For example, if you place the opening bracket to functions, loops, conditional (if) statements etc on the same line as the condition itself (like you do above at the declaration of the function), you'll only have to look for the closing ones.

On the other hand, if you place both opening and closing brackets on their own line your code will be much more vertically symmetrical, which makes it easier to spot missing brackets if you're dealing with larger chunks of code.

You should check out this article that deals with this particular issue: http://encosia.com/in-javascript-curly-brace-placement-matters-an-example/