如何按其中一个字段对数组对象进行分组？

Question

我正在尝试通过从另一个数组列表中过滤来重组数组。

包含过滤器的数组：

const filteringTags: [
    'Kitchen',
    'Accessories',
    ...
]

我想操作的数组：

[
    {
        category: 'free',
        date: '2020-04-04',
        title: 'Some Title',
        tags: [
            'Kitchen',
            'Accessories'
        ]
    },
    {
        category: 'premium',
        date: '2020-04-05',
        title: 'Another Title',
        tags: [
            'Kitchen'
        ]
    },
    ...
]

预期结果：

[
    'Kitchen': [
        {
            category: 'free',
            date: '2020-04-04',
            title: 'Some Title',
            tags: [
                'Kitchen',
                'Accessories'
            ]
        },
        {
            category: 'premium',
            date: '2020-04-05',
            title: 'Another Title',
            tags: [
                'Kitchen'
            ]
        }
    ],
    'Accessories': [
        {
            category: 'free',
            date: '2020-04-04',
            title: 'Some Title',
            tags: [
                'Kitchen',
                'Accessories'
            ]
        }
    ]
]

我试图避免使用库，所以如果您有任何建议，如果您使用 vanilla JS，我将不胜感激。

Answer 1

考虑到所需的 output 作为对象数组，

 const data = [ { category: 'free', date: '2020-04-04', title: 'Some Title', tags: ['Kitchen', 'Accessories'], }, { category: 'premium', date: '2020-04-05', title: 'Another Title', tags: ['Kitchen'], }, ]; const filteringTags = ['Kitchen', 'Accessories']; const getGroupedData = (data, filters) => { const result = {}; filters.forEach(filter => { result[filter] = [...JSON.parse(JSON.stringify((result[filter] || ''))), ...JSON.parse(JSON.stringify(data.filter(d => d.tags.includes(filter)))), ]; }); return result; }; let finalResult = getGroupedData(data, filteringTags); finalResult = Object.keys(finalResult).map(key => ({ [key]: finalResult[key], })); console.log(finalResult);

将 output 视为 object

 const data = [ { category: 'free', date: '2020-04-04', title: 'Some Title', tags: ['Kitchen', 'Accessories'], }, { category: 'premium', date: '2020-04-05', title: 'Another Title', tags: ['Kitchen'], }, ]; const filteringTags = ['Kitchen', 'Accessories']; const getGroupedData = (data, filters) => { const result = {}; filters.forEach(filter => { result[filter] = [...JSON.parse(JSON.stringify((result[filter] || ''))), ...JSON.parse(JSON.stringify(data.filter(d => d.tags.includes(filter)))), ]; }); return result; }; let finalResult = getGroupedData(data, filteringTags); console.log(finalResult);

希望这可以帮助。

Answer 2

const filteringTags = [
  'Kitchen',
  'Accessories',
] 

const arr = [
  {
    category: 'free',
    date: '2020-04-04',
    title: 'Some Title',
    tags: [
        'Kitchen',
        'Accessories'
    ]
},
{
    category: 'premium',
    date: '2020-04-05',
    title: 'Another Title',
    tags: [
        'Kitchen'
    ]
}
]

const resultArr = filteringTags.map((it, index) => {
  return { [it]: arr }
})

如果需要object，那么就用这个function

const resultObj = filteringTags.reduce((acc, it) => {
  return { ...acc, [it]: arr }
}, {})

Answer 3

这是一个完整的工作示例，可产生所需的结果：

 const filteringTags = [ 'Kitchen', 'Accessories', ]; const data = [ { category: 'free', date: '2020-04-04', title: 'Some Title', tags: [ 'Kitchen', 'Accessories' ] }, { category: 'premium', date: '2020-04-05', title: 'Another Title', tags: [ 'Kitchen' ] }, ]; function byTag(tags, data) { let tagMap = {}; for (let tag of tags) { tagMap[tag] = []; for (let datum of data) { if (datum.tags.includes(tag)) { tagMap[tag].push(datum); } } } return tagMap; } let result = byTag(filteringTags, data); console.log(JSON.stringify(result, null, 2));

Answer 4

你可以这样做：

 var arr = [ { category: 'free', date: '2020-04-04', title: 'Some Title', tags: [ 'Kitchen', 'Accessories' ] }, { category: 'premium', date: '2020-04-05', title: 'Another Title', tags: [ 'Kitchen' ] }, ]; var res = arr.reduce((acc, elem)=>{ elem.tags.forEach(k=>{ acc[k] = acc[k]? [...acc[k], JSON.parse(JSON.stringify(elem))]: [JSON.parse(JSON.stringify(elem))]; }) return acc },{}); console.log(res)

Answer 5

你可以这样做：

• reduce()
• filter()

 var filteringTags= [ 'Kitchen', 'Accessories']; var arr=[ { category: 'free', date: '2020-04-04', title: 'Some Title', tags: [ 'Kitchen', 'Accessories' ] }, { category: 'premium', date: '2020-04-05', title: 'Another Title', tags: [ 'Kitchen' ] }]; var result = filteringTags.reduce((acc, e)=>{ acc[e] = arr.filter(k=>k.tags.includes(e)); return acc; },{}); console.log(result);