3 回答

TA貢獻1797條經(jīng)驗 獲得超6個贊
您可以通過date對相同組取消對象的排序、分組并獲得平面數(shù)組。
const
questions = [{ _id: 1, q: 'why?', group: 'no-group', date: '8', selected: false }, { _id: 2, q: 'what?', group: 'group 1', date: '6', selected: false }, { _id: 3, q: 'when?', group: 'no-group', date: '7', selected: false }, { _id: 4, q: 'where?', group: 'group 1', date: '5', selected: false }, { _id: 5, q: 'which?', group: 'group 2', date: '3', selected: false }, { _id: 6, q: 'who?', group: 'no-group', date: '0', selected: false }, { _id: 7, q: 'why not?', group: 'group 2', date: '9', selected: false }, { _id: 8, q: 'who, me?', group: 'group 1', date: '4', selected: false }, { _id: 9, q: 'where is waldo?', group: 'group 1', date: '1', selected: false }, { _id: 10, q: 'which way is up?', group: 'no-group', date: '2', selected: false }, { _id: 11, q: 'when is lunch?', group: 'group 2', date: '10', selected: false }],
result = questions
.sort((a, b) => a.date - b.date)
.map((groups => o => {
if (o.group === 'no-group') return o;
if (groups[o.group]) {
groups[o.group].push(o);
return [];
}
return groups[o.group] = [o];
})({}))
.flat();
console.log(result);
.as-console-wrapper { max-height: 100% !important; top: 0; }

TA貢獻1836條經(jīng)驗 獲得超4個贊
sort
數(shù)組由date
reduce
帶有累加器的數(shù)組Map
。如果它是一個項目,請使用唯一的鍵
no-group
添加一個新條目。Map
_id
如果它是一個有效的項目
group
,則使用group
作為鍵和具有相同的項目數(shù)組group
。每個都
no-group
將作為鍵添加到 Map 中。其余項目將根據(jù)該項目的第一個條目添加group
。獲取
values
地圖并將其擊倒
const questions = [{ _id: 1, q: 'why?', group: 'no-group', date: '8', selected: false }, { _id: 2, q: 'what?', group: 'group 1', date: '6', selected: false }, { _id: 3, q: 'when?', group: 'no-group', date: '7', selected: false }, { _id: 4, q: 'where?', group: 'group 1', date: '5', selected: false }, { _id: 5, q: 'which?', group: 'group 2', date: '3', selected: false }, { _id: 6, q: 'who?', group: 'no-group', date: '0', selected: false }, { _id: 7, q: 'why not?', group: 'group 2', date: '9', selected: false }, { _id: 8, q: 'who, me?', group: 'group 1', date: '4', selected: false }, { _id: 9, q: 'where is waldo?', group: 'group 1', date: '1', selected: false }, { _id: 10, q: 'which way is up?', group: 'no-group', date: '2', selected: false }, { _id: 11, q: 'when is lunch?', group: 'group 2', date: '10', selected: false }]
const group = questions.sort((a, b) => a.date - b.date)
? ? ? ? ? ? ? ? ? ? ? ? .reduce((map, o) =>
? ? ? ? ? ? ? ? ? ? ? ? ? o.group === 'no-group'
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? map.set(o._id, o)
? ? ? ? ? ? ? ? ? ? ? ? ? ? : map.set(o.group, [...map.get(o.group) || [], o] )
? ? ? ? ? ? ? ? ? ? ? ? , new Map)
const output = Array.from(group.values()).flat()
console.log( output )

TA貢獻1829條經(jīng)驗 獲得超6個贊
我們可以date先對它進行排序,然后對對象進行分組,group并將組保存在一個對象中,同時保存組的索引。
然后我們最終可以將組插入到正確的索引處以獲得最終的數(shù)組:
const
groups = [{ _id: 1, q: 'why?', group: 'no-group', date: '8', selected: false }, { _id: 2, q: 'what?', group: 'group 1', date: '6', selected: false }, { _id: 3, q: 'when?', group: 'no-group', date: '7', selected: false }, { _id: 4, q: 'where?', group: 'group 1', date: '5', selected: false }, { _id: 5, q: 'which?', group: 'group 2', date: '3', selected: false }, { _id: 6, q: 'who?', group: 'no-group', date: '0', selected: false }, { _id: 7, q: 'why not?', group: 'group 2', date: '9', selected: false }, { _id: 8, q: 'who, me?', group: 'group 1', date: '4', selected: false }, { _id: 9, q: 'where is waldo?', group: 'group 1', date: '1', selected: false }, { _id: 10, q: 'which way is up?', group: 'no-group', date: '2', selected: false }, { _id: 11, q: 'when is lunch?', group: 'group 2', date: '10', selected: false }];
const sort = (groups) => {
const groupSorted = groups.sort((a, b) => a.date - b.date)
.reduce((r, o, i) => {
if (o.group !== 'no-group') {
r[o.group] = (r[o.group] || []).concat(o);
//insert the index of the group
r.index[o.group] = r.index[o.group] || i;
} else {
r.res.push(o)
}
return r;
}, {
index: {},
res: []
});
Object.entries(groupSorted.index).forEach(([group, idx]) => {
groupSorted.res.splice(idx, 0, groupSorted[group])
});
return groupSorted.res.flat();
}
console.log(sort(groups))
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