替换某个元素
    repalceChild(newNode,targetNode)

    1. <!DOCTYPE html>
    2. <html lang="en">
    3. <head>
    4.     <meta charset="UTF-8">
    5.     <meta name="viewport" content="width=device-width, initial-scale=1.0">
    6.     <title>Document</title>
    7. </head>
    8. <body>
    9.     <div id="app">
    10.         <div ic="child"></div>
    11.     </div>
    12.     <script>
    13.         /*
    14.         替换某个元素
    15.         repalceChild(newNode,targetNode)
    16.         */
    17.         var app = document.getElementById("app");
    18.         var child = document.getElementById("child");
    19.         var p = document.createElement("p");
    20.         p.inerHTML = "hello world";
    21.         app.replaceChild(p.child);
    22.     </script>
    23. </body>
    24. </html>