请问老师问什么url1打印出来没有&

来源：2-4 编程练习

weixin_慕村1291783

2020-11-24 11:14:33

# 具体遇到的问题

# 报错信息的截图

# 相关课程内容截图

# 尝试过的解决思路和结果

# 粘贴全部相关代码，切记添加代码注释（请勿截图）

<!DOCTYPE html><html lang="en">
<head>    <meta charset="UTF-8">    <meta name="viewport" content="width=device-width, initial-scale=1.0">    <title>Document</title></head>
<body>    <script>        // 3.应用        let url = 'https://www.imooc.com/course/list?';        let url1 = 'https://www.imooc.com/course/list?username=xm';        let url2 = 'https://www.imooc.com/course/list?username=xm&';
        const addURLParam = (url, name, value) => {            // 在此补充代码            if (url.includes('?')) {                if (url.includes('?', -1) || url.includes('&', -1)) {                    url += '';                } else {                    url += '&';                }            } else {                url += '?';            }

            url += `${name}=${value}`;            return url;        };        url = addURLParam(url, 'password', 'admin');        url1 = addURLParam(url1, 'password', 'admin');        url2 = addURLParam(url2, 'password', 'admin');        document.write(url, '<br>');        document.write(url1, '<br>');        document.write(url2, '<br>');    </script></body>
</html>