:checked Selector
checked selector
version added: 1.0jQuery(':checked')
描述: 选择所有勾选的元素。
这个 :checked 选择器适用于复选框和单选框。对于下拉框元素, 使用 :selected 选择器。
Example:
Finds all input elements that are checked.
<!DOCTYPE html>
<html>
<head>
  <style>
  div { color:red; }
  </style>
  <script src="http://code.jquery.com/jquery-latest.min.js"></script>
</head>
<body>
  <form>
    <input type="checkbox" name="newsletter" checked="checked" value="Hourly" />
    <input type="checkbox" name="newsletter" value="Daily" />
    <input type="checkbox" name="newsletter" value="Weekly" />
    <input type="checkbox" name="newsletter" checked="checked" value="Monthly" />
    <input type="checkbox" name="newsletter" value="Yearly" />
  </form>
  <div></div>
<script>
    function countChecked() {
      var n = $("input:checked").length;
      $("div").text(n + (n <= 1 ? " is" : " are") + " checked!");
    }
    countChecked();
    $(":checkbox").click(countChecked);
</script>
</body>
</html>Demo:
Result:
<input type="checkbox" name="newsletter" checked="checked" value="Daily" />,
  <input type="checkbox" name="newsletter" checked="checked" value="Monthly" /> ]