JavaScript DHTML/jQuery/Selector first last — различия между версиями

Материал из Web эксперт
Перейти к: навигация, поиск
м (1 версия)
 
м (1 версия)
 
(нет различий)

Текущая версия на 07:23, 26 мая 2010

firstChild(): One for each parent.

  
<html>
  <head>
    <script type="text/javascript" src="js/jquery-1.3.2.js"></script>
    <script type="text/javascript">
        $(document).ready(function(){
                $("div span:first-child")
                .css("text-decoration", "underline")
                .hover(function () {
                      $(this).addClass("red");
                    }, function () {
                      $(this).removeClass("red");
                    });
        });
    </script>
    <style>
    
      span { color:#008; }
      span.red { color:red; font-weight: bolder; }
      
    </style>
  </head>
  <body>
    <body>
      <div>
          <span>A,</span>
          <span>B,</span>
          <span>C</span>
      </div>
      <div>
          <span>D,</span>
          <span>E,</span>
          <span>F</span>
      </div>
    </body>
</html>



first() matches only a single element

  
<html>
  <head>
    <script type="text/javascript" src="js/jquery-1.3.2.js"></script>
    <script type="text/javascript">
        $(document).ready(function(){
                
            $("tr:first").css("background-color", "red");
                
        });
    </script>
  </head>
  <body>
    <body>
    <table border="1">
        <tr><td>TD #0</td><td>TD #1</td><td>TD #2</td></tr>
        <tr><td>TD #3</td><td>TD #4</td><td>TD #5</td></tr>
        <tr><td>TD #6</td><td>TD #7</td><td>TD #8</td></tr>
    </table>
    </body>
</html>



Get first child ID

     

<html>
  <head>
    <script type="text/javascript" src="js/jquery-1.3.2.js"></script>
    <script type="text/javascript">
        $(document).ready(function(){
           $("#container").click(function (e) {
              var $ch = $(e.target).children();
              
              $("#results span:first").text($ch.length);
              
              e.preventDefault();
              return false;
            });
        });
    </script>
  </head>
  <body>
    <body>
    <div id="container">
        <div>
          <p>This <span>is the <em>way</em> we</span> 
          write <em>the</em> demo,</p>
        </div>
        
    </div>
    <span id="results">Found <span>0</span> children in <span>TAG</span>.</span>
  </body>
</html>



Get first paragraph

     
<html>
  <head>
    <script type="text/javascript" src="js/jquery-1.3.2.js"></script>
    <script type="text/javascript">
        $(document).ready(function(){
               var str = $("p:first").text()+"added";
               $("p:last").html(str);

        });
    </script>
  </head>
  <body>
    <body>
         <p>asdf</p>
         <p>asdf</p>
         <p>asdf</p>
         <p>asdf</p>
  </body>
</html>



Get last paragraph

      
<html>
  <head>
    <script type="text/javascript" src="js/jquery-1.3.2.js"></script>
    <script type="text/javascript">
        $(document).ready(function(){
               var str = $("p:first").text()+"added";
               $("p:last").html(str);

        });
    </script>
  </head>
  <body>
    <body>
         <p>asdf</p>
         <p>asdf</p>
         <p>asdf</p>
         <p>asdf</p>
  </body>
</html>



lastChild() : One for each parent.

  

<html>
  <head>
    <script type="text/javascript" src="js/jquery-1.3.2.js"></script>
    <script type="text/javascript">
        $(document).ready(function(){
                $("div span:last-child")
                .css("text-decoration", "underline")
                .hover(function () {
                      $(this).addClass("red");
                    }, function () {
                      $(this).removeClass("red");
                    });
        });
    </script>
    <style>
    
      span { color:#008; }
      span.red { color:red; font-weight: bolder; }
      
    </style>
  </head>
  <body>
    <body>
      <div>
          <span>A,</span>
          <span>B,</span>
          <span>C</span>
      </div>
      <div>
          <span>D,</span>
          <span>E,</span>
          <span>F</span>
      </div>
    </body>
</html>



last() matches the last selected element.

  
<html>
  <head>
    <script type="text/javascript" src="js/jquery-1.3.2.js"></script>
    <script type="text/javascript">
        $(document).ready(function(){
           $("tr:last").css({backgroundColor: "yellow", fontWeight: "bolder"});
        });
    </script>
  </head>
  <body>
    <body>
    <table>
        <tr><td>First</td></tr>
        <tr><td>Middle</td></tr>
        <tr><td>Last</td></tr>
    </table>

    </body>
</html>



Matches the first selected element

      
<html>
  <head>
    <script type="text/javascript" src="js/jquery-1.3.2.js"></script>
    <script type="text/javascript">
  $(document).ready(function(){
      $("tr:first").css("font-style", "italic");
  });
    </script>
  </head>
  <body>
      <table>
        <tr><td>Row 1</td></tr>
        <tr><td>Row 2</td></tr>
        <tr><td>Row 3</td></tr>
      </table>

  </body>
</html>



Matches the last selected element

      
<html>
  <head>
    <script type="text/javascript" src="js/jquery-1.3.2.js"></script>
    <script type="text/javascript">
  $(document).ready(function(){
      $("tr:last").css("font-style", "italic");
  });
    </script>
  </head>
  <body>
      <table>
        <tr><td>Row 1</td></tr>
        <tr><td>Row 2</td></tr>
        <tr><td>Row 3</td></tr>
      </table>

  </body>
</html>



Select first span

     
<html>
  <head>
    <style>
      .test{ border: 1px solid red; }
    </style>
  
    <script type="text/javascript" src="js/jquery-1.3.2.js"></script>
    <script type="text/javascript">
    $(document).ready(function(){
           $("span:first").text($(":hidden", document.body).length + " hidden elements.");
    });
    </script>

  </head>
  <body>
      <span></span>
        <div></div>
        <div style="display:none;">Hider!</div>
        <div></div>
        <div></div>
        <form>
            <input type="hidden" />
            <input type="hidden" />
            <input type="hidden" />
        </form>
        <span></span>
  </body>
</html>
Источник — «http://wbex.ru/index.php?title=JavaScript_DHTML/jQuery/Selector_first_last&oldid=2801»