後臺返回的數據：

[
  {confirmCharge: "0.00", orderId: "--", changeId: "1", realName: "王五", totalConfirmCharge: "0.00",…},
  {confirmCharge: "0.00", orderId: "288783482594267136", changeId: "", realName: "王五",…},
  {confirmCharge: "0.00", orderId: "--", changeId: "1", realName: "王五", totalConfirmCharge: "0.00",…},
  {1: 1, totalOrderTimes: 2}
]
 

要求：

changeId相同的項，只取一條數據，changeId為空，原樣取出，最後一條數據不取

目標數據：

[
  {confirmCharge: "0.00", orderId: "--", changeId: "1", realName: "王五", totalConfirmCharge: "0.00",…},
  {confirmCharge: "0.00", orderId: "288783482594267136", changeId: "", realName: "王五",…}
]

思路：

把changeId屬性值存到一個arr數組，存目標數據前將每一項的changeId和arr中的值進行對比，如果相同，就不取該項

實現代碼：

var arr = [],ifContain 
var objArr = [
  {confirmCharge: "0.00", orderId: "--", changeId: "1", realName: "王五", totalConfirmCharge: "0.00",…},
  {confirmCharge: "0.00", orderId: "288783482594267136", changeId: "", realName: "王五",…},
  {confirmCharge: "0.00", orderId: "--", changeId: "1", realName: "王五", totalConfirmCharge: "0.00",…},
  {
 
1: 1, totalOrderTimes: 2}
]
var newArr = []
// console.log(arr) 
// arr用來存儲changeId  ifContain用來判斷當前元素中的changId是否在arr中
newArr.push(objArr[0])
if(objArr[0].changeId){
    arr.push(objArr[0].changeId)
}

for(var i=1;i<objArr.length-1;i++){
    if(!objArr[i].changeId){
        newArr.push(objArr[i])
    }if(objArr[i].changeId){
        ifContain = contains(arr,objArr[i].changeId)
        if(!ifContain){
            newArr.push(objArr[i])
            arr.push(objArr[i].changeId)
        }
    }
}

    // JS判斷元素是否在數組內的實現代碼
contains(arr,obj) {
    let length = arr.length
    while(length--){
        if(arr[length] === obj){
            return true
        }
    }
    return false
}

後臺返回對象數組，對象屬性相同時，只取一個對象