javascript - 影响父方法变量的递归调用？

Question

我正在构建嵌套评论。我的 AJAX 脚本获取如下注释列表并扩展它们 -

    if (xmlhttp.readyState == 4 || myOb.readyState == "complete")   {
        // EVAL
        var comments = eval('(' + xmlhttp.responseText + ')');

        // POPULATE
        var comm = "<ul>";
        for(i = 0; i < comments.length; i++)    {               
            if(comments[i].replyto == 0)    {
                comm = comm + expand(property, comments, i);
            }
        }
        comm = comm + "</ul>";
        // DISPLAY
        document.getElementById("comments").innerHTML = comm;
    }

这里，expand 函数是递归的，而且似乎引起了麻烦 -

function expand(property, comments, k)  {
    var comm = "";

    // PRINT MAIN COMMENTS
    comm = comm + "<li>";
        // print otherparent comment data

        // replies
        comm = comm + "<ul>";
        for(i = 0; i < comments.length; i++)    {
            // is a reply?
            if(comments[i].replyto == comments[k].id)   {
                comm = comm + expand(property, comments, i);
            }
        }
        comm = comm + "</ul>";

    comm = comm + "</li>";
    return comm;
}

这个脚本最终只给出了第一个 comments 数组元素(及其各自的子评论)。但是如果我删除递归代码，我就不会遇到那个问题(而且，我不没有得到任何子评论)..

function expand(property, comments, k)  {
    var comm = "";

    // PRINT MAIN COMMENTS
    comm = comm + "<li>";
        // print otherparent comment data

        // replies
        comm = comm + "<ul>";
        /*
        for(i = 0; i < comments.length; i++)    {
            // is a reply?
            if(comments[i].replyto == comments[k].id)   {
                comm = comm + expand(property, comments, i);
            }
        }
        */
        comm = comm + "</ul>";

    comm = comm + "</li>";
    return comm;
}

我在 eval 函数中设置了两个警报，在 expand 调用之前和之后各一个:

        for(i = 0; i < comments.length; i++)    {               
            if(comments[i].replyto == 0)    {
                alert(i);
                comm = comm + expand(property, comments, i);
                alert(i);
            }
        }

两者都给了我不同的 i 值。我做错了什么？

谢谢

Answer 1

您忘记将“i”设为局部变量:

    for(var i = 0; i < comments.length; i++)    {               

这真的很重要。