javascript - 根据对象中字段的存在对数组进行排序

Question

如果缺少任何字段，如何对如下所示的数组进行排序？

例如，现有数组是:

const users = [
    {
        id: 1, firstname: 'Jerry'
    }, {
        id: 2, firstname: 'Thomas', lastname: 'Geib'
    }, {
        id: 3
    }, {
        id: 4, lastname: 'Berg'
    }, {
        id: 5, firstname: 'Ass', lastname: 'Noob'
    }, {
        id: 6, lastname: 'Jopa'
    }
]

结果应按以下顺序排序:

1. 具有名字和姓氏的对象
2. 仅包含名字或姓氏的对象
3. 不带名字和姓氏的对象

这样它看起来像:

    const users = [
        {
            id: 2, firstname: 'Thomas', lastname: 'Geib'
        }, {
            id: 5, firstname: 'Ass', lastname: 'Noob'
        }, {
            id: 1, firstname: 'Jerry'
        }, {
            id: 4, lastname: 'Berg'
        }, {
            id: 6, lastname: 'Jopa'
        }, {
            id: 3
        }
    ]

我尝试过这种排序，但结果不是我需要的

users.sort((a,b) => {
    if (a.firstname === b.firstname) {
        return 0
    }
    if (!a.firstname) {
        return 1
    }
    return -1
});

Answer 1

您可以通过检查该属性是否存在来排序。最后按 id 升序排序。

const users = [{ id: 1, firstname: 'Jerry' }, { id: 2, firstname: 'Thomas', lastname: 'Geib' }, { id: 3 }, { id: 4, lastname: 'Berg' }, { id: 5, firstname: 'Ass', lastname: 'Noob' }, { id: 6, lastname: 'Jopa' }];

users.sort((a, b) => 
    ('firstname' in b && 'lastname' in b ) - ('firstname' in a && 'lastname' in a) ||
    ('firstname' in b) - ('firstname' in a) ||
    ('lastname' in b) - ('lastname' in a) ||
    a.id - b.id
);

console.log(users);

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