HTML | DOM setNamedItem() 方法

setNamedItem()方法用于使用名称将特定节点添加到属性节点。这些属性节点统称为namedNodeMap。它可以通过名称访问。如果文档中已经存在一个节点，它将替换它并返回更新后的值。 setNamedItem()方法需要一个节点作为参数。
句法：

namedNodeMap.setNamedItem( node )

参数值：此方法包含单个参数节点，这是强制性的。该参数是namedNodeMap集合中需要添加或替换的节点值。

返回值：它返回一个 Node 对象，表示被替换的节点（如果有），否则为 null

示例 1：

HTML

    
        
            DOM setNamedItem() Method
        
         
        
            .gfg {
                color:green;
                font-size: 40px;
            }
        
    
     
    
        GeeksforGeeks
        DOM setNamedItem() Method
         
        
            Set Node
        
         
        
            function setNameItem() {
                 
                // It is used to fetch the text
                // present in class geeks1
                var one =
                    document.getElementsByClassName("geeks1")[0];
                 
                // New class (geek) is created
                var geek = document.createAttribute("class");
                 
                // Passing value of gfg class into geek class
                geek.value = "gfg";                                
                 
                // Updating the CSS property of geeks1
                // class to gfg class
                one.attributes.setNamedItem(geek);                    
            }
        
    

输出：
点击按钮前：

点击按钮后：

示例 2：

HTML

    
        
            DOM setNamedItem() Method
        
         
        
        
            .gfg {
                color:green;
                font-size: 40px;
            }
            .gfg1 {
                color:green;
                font-size: 40px;
            }
        
    
     
    
         
        GeeksforGeeks
        DOM setNamedItem() Method
        Welcome to GeeksforGeeks
         
        
            Set Node
        
         
        
            function setNameItem() {
                 
                var one =
                    document.getElementsByTagName("H1")[0];
                var geek =
                    document.createAttribute("class");
                geek.value = "gfg";                            
                one.attributes.setNamedItem(geek);            
         
                var two =
                    document.getElementsByTagName("H3")[0];
                var geek1 =
                    document.createAttribute("class");
                geek1.value = "gfg1";
                two.attributes.setNamedItem(geek1);
            }
        
    
                                      

输出：
点击按钮前：

点击按钮后：

支持的浏览器： DOM setNamedItem() 方法支持的浏览器如下：

• 谷歌浏览器
• IE浏览器
• 火狐
• 歌剧
• 苹果浏览器