我正在尝试实现一个排序函数，该函数接受对象数组并按属性或嵌套属性对它们进行排序。我在这里查看了大量问题，并对这个问题给出了很好的答案，但据我所知，它们都没有解释何时缺少嵌套属性。
例如，如果我对数组元素之一按 some_attribute 和 some_attribute = undefined 进行排序，则相关元素将被移至数组的末尾/开头，正如我所料。如果我按 some_attribute.something_else 排序，当 some_attribute.something_else = undefined 时，我看到的函数响应不佳。
这是我尝试排序的数据结构示例:
results = [
{
id: 233,
post: "Test 944 AM http://frmply.co/1mA9G3L",
twitter_favorite_count: 0,
twitter_retweet_count: 2,
twitter_link_click_count: {
minute: null,
hour: null,
day: null,
week: null,
month: null,
total: 3
},
twitter_last_updated: "2015-12-28T21:11:27.425Z",
facebook_like_count: null,
facebook_share_count: 1,
facebook_comment_count: null,
facebook_link_click_count: {
minute: null,
hour: null,
day: null,
week: null,
month: null,
total: 1
},
facebook_last_updated: "2015-12-28T21:11:29.232Z",
linkedin_like_count: null,
linkedin_comment_count: null,
linkedin_link_click_count: {
minute: null,
hour: null,
day: null,
week: null,
month: null,
total: 0
},
linkedin_last_updated: "2015-12-28T21:11:29.905Z"
},
{
id: 232,
post: "Test 944 AM http://frmply.co/1mA9G3L",
twitter_favorite_count: null,
twitter_retweet_count: null,
twitter_link_click_count: {
minute: null,
hour: null,
day: null,
week: null,
month: null,
total: 5
},
twitter_last_updated: null,
facebook_like_count: null,
facebook_share_count: null,
facebook_comment_count: null,
facebook_link_click_count: { },
facebook_last_updated: null,
linkedin_like_count: null,
linkedin_comment_count: null,
linkedin_link_click_count: { },
linkedin_last_updated: null
},
{
id: 234,
post: "localhost test 1106am http://frmply.co/1RAYalE",
twitter_favorite_count: 0,
twitter_retweet_count: 0,
twitter_link_click_count: {
minute: null,
hour: null,
day: null,
week: null,
month: null,
total: 2
},
twitter_last_updated: "2016-01-06T18:40:21.388Z",
facebook_like_count: null,
facebook_share_count: null,
facebook_comment_count: null,
facebook_link_click_count: {
minute: null,
hour: null,
day: null,
week: null,
month: null,
total: 0
},
facebook_last_updated: "2015-12-29T16:07:39.042Z",
linkedin_like_count: null,
linkedin_comment_count: null,
linkedin_link_click_count: {
minute: null,
hour: null,
day: null,
week: null,
month: null,
total: 0
},
linkedin_last_updated: "2015-12-29T16:07:39.489Z"
},
{
id: 231,
post: "test",
twitter_favorite_count: null,
twitter_retweet_count: null,
twitter_link_click_count: { },
twitter_last_updated: null,
facebook_like_count: null,
facebook_share_count: null,
facebook_comment_count: null,
facebook_link_click_count: { },
facebook_last_updated: null,
linkedin_like_count: null,
linkedin_comment_count: null,
linkedin_link_click_count: { },
linkedin_last_updated: null
}
]
现在，如果我运行下面的代码，当我期望 [undefined, 2, 3, 5] 时，我会得到 [2, 3, 5, undefined] 结果>.
results.sortBy('twitter_link_click_count.total').map(function(x){return x.twitter_link_click_count.total})
在上面的代码片段中，sortBy 是 this post 中的函数。 ，但是我也尝试使用 Underscore 的 _.sortBy 函数获得相同的结果。
工作代码
这是我根据 Oleg 的回答提出的解决方案:
var sortKey = attribute.split('.');
var sortBy = function(results, sortKey) {
return _.sortBy(results, function(item) {
if(sortKey.length === 1) {
return item[sortKey[0]] || 0;
} else {
return item[sortKey[0]][sortKey[1]] || 0;
};
});
};
这里的关键区别在于它生成一个 sortKey 数组，该数组可以用于 if/else 语句或迭代。我使用了 if/else，因为我的 sortKey 仅位于对象内部的 1 或 2 层深处。我还通过返回 0 而不是 true 来处理属性为 null 的情况。希望这对其他人有帮助。
最佳答案
请尝试以下脚本(此处使用下划线):
results = [
{
id: 233,
post: "Test 944 AM http://frmply.co/1mA9G3L",
twitter_favorite_count: 0,
twitter_retweet_count: 2,
twitter_link_click_count: {
minute: null,
hour: null,
day: null,
week: null,
month: null,
total: 3
},
twitter_last_updated: "2015-12-28T21:11:27.425Z",
facebook_like_count: null,
facebook_share_count: 1,
facebook_comment_count: null,
facebook_link_click_count: {
minute: null,
hour: null,
day: null,
week: null,
month: null,
total: 1
},
facebook_last_updated: "2015-12-28T21:11:29.232Z",
linkedin_like_count: null,
linkedin_comment_count: null,
linkedin_link_click_count: {
minute: null,
hour: null,
day: null,
week: null,
month: null,
total: 0
},
linkedin_last_updated: "2015-12-28T21:11:29.905Z"
},
{
id: 232,
post: "Test 944 AM http://frmply.co/1mA9G3L",
twitter_favorite_count: null,
twitter_retweet_count: null,
twitter_link_click_count: {
minute: null,
hour: null,
day: null,
week: null,
month: null,
total: 5
},
twitter_last_updated: null,
facebook_like_count: null,
facebook_share_count: null,
facebook_comment_count: null,
facebook_link_click_count: { },
facebook_last_updated: null,
linkedin_like_count: null,
linkedin_comment_count: null,
linkedin_link_click_count: { },
linkedin_last_updated: null
},
{
id: 234,
post: "localhost test 1106am http://frmply.co/1RAYalE",
twitter_favorite_count: 0,
twitter_retweet_count: 0,
twitter_link_click_count: {
minute: null,
hour: null,
day: null,
week: null,
month: null,
total: 2
},
twitter_last_updated: "2016-01-06T18:40:21.388Z",
facebook_like_count: null,
facebook_share_count: null,
facebook_comment_count: null,
facebook_link_click_count: {
minute: null,
hour: null,
day: null,
week: null,
month: null,
total: 0
},
facebook_last_updated: "2015-12-29T16:07:39.042Z",
linkedin_like_count: null,
linkedin_comment_count: null,
linkedin_link_click_count: {
minute: null,
hour: null,
day: null,
week: null,
month: null,
total: 0
},
linkedin_last_updated: "2015-12-29T16:07:39.489Z"
},
{
id: 231,
post: "test",
twitter_favorite_count: null,
twitter_retweet_count: null,
twitter_link_click_count: { },
twitter_last_updated: null,
facebook_like_count: null,
facebook_share_count: null,
facebook_comment_count: null,
facebook_link_click_count: { },
facebook_last_updated: null,
linkedin_like_count: null,
linkedin_comment_count: null,
linkedin_link_click_count: { },
linkedin_last_updated: null
}
];
document.getElementById('output').innerHTML = JSON.stringify(_.sortBy(results, function(item) {
return item.twitter_link_click_count.total || true;
}).map(function(x){return x.twitter_link_click_count.total}));<script src="http://underscorejs.org/underscore-min.js"></script>
<pre id="output"></pre>关于Javascript 使用嵌套属性对对象数组进行排序，其中某些属性未定义，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/34644272/