JavaScript遍历DOM对象属性与指定属性详解

<!DOCTYPE html>
<html>

<body>
  <button id="btnToggleState" onclick="toggleStateManagement()">
      Disable State
  </button>
</body>
<script>
  var obj = document.getElementById("btnToggleState");
  var s = "";
  for (var elem in obj) {
    s += elem + "\n";
  }
  alert(s);
</script>
</html>

<!DOCTYPE html>
<html>

<body>
  <button id="btnToggleState" onclick="toggleStateManagement()">
      Disable State
    </button>
</body>
<script>
  // var obj = document.getElementById("btnToggleState");
  // var s = "";
  // for (var elem in obj) {
  //   s += elem + "\n";
  // }
  // alert(s);


  var obj = document.getElementById("btnToggleState");
  var pairs = new Array();
  for (var i = 0, len = obj.attributes.length; i < len; i++) {
    var name = obj.attributes[i].nodeName;
    var value = obj.attributes[i].nodeValue;
    if (obj.attributes[i].specified) {
      pairs.push(name + "=\' " + value + "\' ")
    }
  }
  alert(pairs);
</script>

</html>