<html>
    <head>
        <meta charset=utf-8>
    </head>
    <body>
        <ul></ul>
    </body>
    <script type="text/javascript">
        function createLi(array){
            // 补全代码
            var ul = document.querySelector('ul');
            for(var i = 0; i < array.length; i++) {
                var li = document.createElement('li');
                li.innerHTML = array[i];
                ul.appendChild(li);
            }
        }
    </script>
</html>
  1. 获取ul元素
  2. 循环遍历数组，创建li
  3. 给他加值
  4. 把li放进ul中