How to detect the selected checkboxes using JavaScript

Programming, JavaScript

Here is an example of how you can retrieve the selected checkboxes using a JavaScript function:

  
<html>
<head>
<script>
function getSelectedValues(elem) {
  var elemNumber = document.myForm.test.length;

  var selectedElems = [];
  for(j = 0; j < elemNumber; j++) {
    if(elem[j].checked) {
      selectedElems.push(elem[j].value);
    }
  }
  return selectedElems;
}
</script>
</head>

<body>
<form id="myForm" name="myForm">
<input type="checkbox" id="test" name="myCheckBox" value="test1">
Test 1


<input type="checkbox" id="test" name="myCheckBox" value="test2">
Test 2


<input type="button" value="Click Here" 
  onclick="alert(getSelectedValues(document.myForm.myCheckBox));">
</form>
</body>

</html>

In the previous example when the user clicks on the button the selected checkboxes are displayed through an alert.