innerHTML：给元素添加内容

    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.     <ul id="app">
    10.         <li>html</li>
    11.         <li id="js">javascript</li>
    12.     </ul>
    13.     <script>
    14.         // 给元素添加内容innerHTML
    15.         var app = document.getElementById("app");
    16.         var js = document.getElementById("js");
    17.         var li = document.createElement("li");
    18.         li.innerHTML="vue";
    19.         app.insertBefore(li,js);
    20.     </script>
    21. </body>
    22. </html>

    1.PNG