jQuery :focus 选择器

jQuery :focus选择器是用来选择当前文档中所有有焦点的元素。它也可以与标签名称一起使用或使用另一个选择器。

语法:

$(":focus")

示例 1:

<!DOCTYPE html>
<html>
<head>
  <script src=
"https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js">
  </script>
  <script>
    (document).ready(function () {
      ("input").focus();
      $(":focus").css(
        "background-color", "green");
    });
  </script>
</head>
<body>
  <center>
    <h1 style="color:green;">
      GeeksForGeeks
    </h1>
    <h2> jQuery :focus Selector </h2>
    Name:
    <input type="text"/>
    <br>
    Password:
    <input type="text"/>
    <br>
    <button>Submit</button>
  </center>
</body>
</html>

输出:

jQuery :focus 选择器

示例 2:

<!DOCTYPE html>
<html>
<head>
  <script src=
"https://ajax.googleapis.com/ajax/libs/jquery/3.6.0/jquery.min.js">
  </script>
  <script>
    (document).ready(function () {
      ("button").click(function () {
        ("textarea").focus();
          (":focus").css("font-size", "25px");
      });
    });
  </script>
</head>
<body>
  <center>
    <h1 style="color:green;">
      GeeksforGeeks
    </h1>
    <h2> jQuery :focus Selector </h2>
    <textarea>GeeksforGeeks</textarea>
    <br>
    <textarea>Learning Together!</textarea>
    <br>
    <button>Change</button>
  </center>
</body>
</html>