按3個值對JavaScript數組排序

Question

我想按三個值對這個JavaScript數組進行排序，但是我似乎無法弄清楚如何一次按多個屬性進行排序。

要求是：

1. featured商品應放在最頂端
2. 然后沒有名稱的項目（ null ）
3. 然后用姓名的物品不被featured
4. 按createdAt的降序對所有內容進行排序（ createdAt到舊）

這是數組：

var items [
    { name: 'foo-1', featured: true,  createdAt: 1493000001 },
    { name: null,    featured: false, createdAt: 1493000003 },
    { name: 'foo-3', featured: true,  createdAt: 1493000002 },
    { name: 'foo-4', featured: false, createdAt: 1493000004 },
    { name: 'foo-5', featured: false, createdAt: 1493000005 },
];

結果應為：

[
    { name: 'foo-3', featured: true,  createdAt: 1493000002 },
    { name: 'foo-1', featured: true,  createdAt: 1493000001 },
    { name: null,    featured: false, createdAt: 1493000003 },
    { name: 'foo-5', featured: false, createdAt: 1493000005 },
    { name: 'foo-4', featured: false, createdAt: 1493000004 },
]

Answer 1

 var items = [ { name: 'foo-1', featured: true, createdAt: 1493000001 }, { name: null, featured: false, createdAt: 1493000003 }, { name: 'foo-3', featured: true, createdAt: 1493000002 }, { name: 'foo-4', featured: false, createdAt: 1493000004 }, { name: 'foo-5', featured: false, createdAt: 1493000005 }, ]; items.sort(function(a, b) { if(a.featured && !b.featured) return -1; // if a is featured and b is not, then put a above b if(!a.featured && b.featured) return 1; // if b is featured and a is not, then put b above a if(!a.name && b.name) return -1; // if a doesn't have a name and b does, then put a above b if(a.name && !b.name) return 1; // if b doesn't have a name and a does, then put b above a return b.createdAt - a.createdAt; // otherwise (a and b have simillar properties), then sort by createdAt descendently }); console.log(items); 

Answer 2

您可以使用一個比較函數，該函數可以作為參數傳遞給sort（）函數-有關更多詳細信息，請參見Array.prototype.sort（） 。 在您的情況下，compare函數可能如下所示：

var items = [
    { name: 'foo-1', featured: true,  createdAt: 1493000001 },
    { name: null,    featured: false, createdAt: 1493000003 },
    { name: 'foo-3', featured: true,  createdAt: 1493000002 },
    { name: 'foo-4', featured: false, createdAt: 1493000004 },
    { name: 'foo-5', featured: false, createdAt: 1493000005 },
];

function compare(a, b) {
    if (a.featured === true && b.featured === false) return -1;
    if (a.featured === false && b.featured === true) return 1;
    if (a.name === null && b.featured !== null) return -1;
    if (a.name !== null && b.name === null) return 1;

    return b.createdAt - a.createdAt;
};

items.sort(compare);

當名稱是一個空字符串時，它應該涵蓋這種情況。