javascript - jQuery .forEach() 导致错误， "undefined is not a function"

Question

我收到错误，undefined is not a function 行 entries.forEach(function(e) { 我不知道为什么。可以有人帮忙吗？

当我将它传递给函数时，我确定条目被定义为下面的原型(prototype)。

这是我正在处理的功能:

function score_relevance3(entries, usr_tags) {

    entries.forEach(function(e) 
    {
        entries[e].count = 0;
        entries[e].tags.forEach(function(i) 
        {
            usr_tags.forEach(function(f) 
            {
                if (entries[e].tags[i] === usr_tags[f]) 
                {
                    entries[e].count++;
                }
            });
        });
    });

    return entries;
}

这是我的 entries 对象的原型(prototype):

entries = {
"1":{"tags":["1","2"]},
"2":{"tags":["1","3","2"]},
"3":{"tags":["1","2"]},
"4":{"tags":["1","2"]},
"5":{"tags":["1","2"]},
"6":{"tags":["4","5","6","2"]},
"7":{"tags":["4","7"]},
"8":{"tags":["4","8","3"]},
"9":{"tags":["4","9"]}
};

Answer 1

就像 elclanrs 在评论中提到的那样，您不能在对象上调用 forEach，只能在数组上调用。如果要遍历条目，请使用:

for (entry in entries) { ...