js radio是否被选中

<form id="myForm">
  <input type="radio" name="gender" value="male" id="male">
  <label for="male">Male</label><br>
  <input type="radio" name="gender" value="female" id="female">
  <label for="female">Female</label><br>
  <input type="radio" name="gender" value="other" id="other">
  <label for="other">Other</label><br>
  <button type="button" onclick="checkRadio()">Check Selection</button>
</form>

function checkRadio() {
  var radios = document.getElementsByName('gender');
  var selectedValue = null;

  for (var i = 0; i < radios.length; i++) {
    if (radios[i].checked) {
      selectedValue = radios[i].value;
      break;
    }
  }

  alert('Selected value: ' + selectedValue);
}

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