jQuery | index() 示例

index()是 jQuery 中的一个内置方法，用于返回与选择器相关的指定元素的索引。
句法：

$(selector).index(element)

参数：它接受一个可选参数“元素”，用于获取元素的位置。
返回值：它返回一个整数，表示指定元素的索引。

显示 index()函数工作的 jQuery 代码：
代码#1：

  

    
    
    
        <!--jQuery code to demonstrate index function -->
  
        // document ready
        $(document).ready(function() {
            // if the list is clicked
            $("li").click(function() {
                // index() 
                // to return the index of the clicked
                // element of the list
                document.getElementById("demo").innerHTML = "Clicked Index "
                                                            + $(this).index();
            });
        });
    

  

  
    Click on the elements of the list to display their index
       number with respect to the other elements in the list.
  
    
        Geeks
        for
        Geeks
    
  
    

  

输出：
在单击列表中的任何元素之前

Click on the elements of the list to display their index number with 
respect to the other elements in the list.

• 极客
• 为了
• 极客

点击“for”后——

Click on the elements of the list to display their index number with 
respect with the other elements in the list.

• 极客
• 为了
• 极客

单击索引 1

代码#2：

  

    
    
    
        <!--jQuery code to demonstrate index function -->
  
        // document ready
        $(document).ready(function() {
            // if the list is clicked
            $("li").click(function() {
                // index() 
                // to return the index of the clicked
                // element of the list
                document.getElementById("demo").innerHTML = "Clicked Index "
                                    + $($(".myclass")).index($("#id"));
            });
        });
    

  

  
    Click on the elements of the list to display their index
       number with respect with the other elements in the list.
  
    
        Geeks
        for
        Geeks
    
  
    

  

输出：
在单击列表中的任何元素之前 -

Click on the elements of the list to display their index number with 
respect with the other elements in the list.

• 极客
• 为了
• 极客

单击列表中的任何元素后-

Click on the elements of the list to display their index number with 
respect with the other elements in the list.

• 极客
• 为了
• 极客

点击索引 1