js 數(shù)組對象處理

arr1=arr.filter((entity)=>{entity.sequenceNumber==1});
arr2=....
以此類推，不寫了

我的思路：循環(huán)兩次，外層拿到的對象作為參照對象，和內層循環(huán)到的對象依次做對比，找到一樣的就拿到它的weekDay值push給參照對象，然后刪除掉。

因為初始weekDay是number型，找到之后還要轉換成數(shù)組才行。

    var arr = [
        { weekDay: 0, sequenceNumber: 1 }, 
        { weekDay: 0, sequenceNumber: 2 }, 
        { weekDay: 1, sequenceNumber: 2 }, 
        { weekDay: 2, sequenceNumber: 3 }, 
        { weekDay: 3, sequenceNumber: 3 }, 
        { weekDay: 6, sequenceNumber: 3 }
    ];
    for(let i = 0; i < arr.length; i++) {
        arr.map((m, n) => {
            if (arr[i].sequenceNumber === m.sequenceNumber && i !== n) {
                // 將參照對象的weekDay轉換成數(shù)組
                arr[i].weekDay = [arr[i].weekDay]
                // 將該對象的weekDay值push到參照對象中，并刪除
                arr[i].weekDay.push(m.weekDay)
                arr.splice(n, 1)
            }
        })
    }
    
    console.log(arr)

遍歷數(shù)組，然后根據(jù)sequenceNumber的值push到不同的數(shù)組里面。

let data = [
  {backupType: "全備", weekCycle: 1, weekDay: 0, sequenceNumber: 1},
  {backupType: "全備", weekCycle: 1, weekDay: 0, sequenceNumber: 2},
  {backupType: "全備", weekCycle: 1, weekDay: 1, sequenceNumber: 2},
  {backupType: "全備", weekCycle: 1, weekDay: 2, sequenceNumber: 3},
  {backupType: "全備", weekCycle: 1, weekDay: 3, sequenceNumber: 3},
  {backupType: "全備", weekCycle: 1, weekDay: 6, sequenceNumber: 3}
]

let cache = {}
data = data.filter(item => {
  let num = item.sequenceNumber
  let weekDay = item.weekDay
  let tmp = cache[num]

  if (tmp) {
    let tmpWeekDay = tmp.weekDay
    if (Array.isArray(tmpWeekDay)) {
      tmpWeekDay.push(weekDay)
    } else {
      tmp.weekDay = [tmpWeekDay, weekDay]
    }
    return false
  } else {
    cache[num] = item
    return true
  }
})