AJAX XMLHttpRequest错误

Question

I have this basic "GET" request on a demo page I'm building via localhost. 我在通过localhost构建的演示页面上有这个基本的“ GET”请求。 Both json and html file are in the same folder. json和html文件都在同一文件夹中。

http://localhost.com/test.html
http://localhost.com/myList.json

Unfortunately when making the request I get this error: 不幸的是，在发出请求时出现此错误：

Uncaught ReferenceError: results is not defined.

Uncaught TypeError: Cannot set property 'innerHTML' of null

My html is as follows. 我的HTML如下。

    <html>
<head>
    <title>Test</title>
    <script type="text/javascript">
    function get_json_request() {
        var httpRequest;
        httpRequest = new XMLHttpRequest();
        httpRequest.open("GET", "myList.json", true);
        httpRequest.setRequestHeader("Content-type", "application/json", true);
        httpRequest.onreadystatechange = function() {
            if (httpRequest.readyState === 4 && httpRequest.status === 200) {
                var data = JSON.parse(httpRequest.responseText);
                var results = document.getElementById("results");
                results.innerHTML = data.user;
            } else {
                alert('There was a problem with the request.');
                }
            }
        httpRequest.send(null); 
        results.innerHTML = "Processing....";
    }
</script>
</head>
<body>
    <div id"results"></div> 
    <script type="text/javascript">get_json_request();</script>
</body>
</html>

Any help appreciated. 任何帮助表示赞赏。

Answer 1

You're setting the reference to "results" in a conditional statement. 您在条件语句中设置对“结果”的引用。 If that variable is not initialised, it will naturally return null. 如果未初始化该变量，则它自然会返回null。

AJAX XMLHttpRequest错误

问题描述

1 个解决方案

解决方案1
1 2013-07-01 21:20:49

AJAX XMLHttpRequest错误

问题描述

1 个解决方案

解决方案1 1 2013-07-01 21:20:49

解决方案1
1 2013-07-01 21:20:49