如何根据bstatus优先级去除对象数组中的重复id项

去重规则 #

• 同一id存在多条数据时，优先保留bstatus:"confirm"的条目，过滤其余同id重复项
• 若同id下无confirm状态条目、仅存在checkout状态条目，则保留bstatus:"checkout"的条目
• 需过滤排除bstatus:"reserve"、status:"cancel"的条目

原始测试数组 #

[
    {
        "id": "1",
        "room_no": "Room No 101",
        "status": "confirm",
        "created_at": "2021-10-27 17:41:05",
        "bid": "70",
        "rid": "1",
        "guest_name": "test",
        "tariff": "2000",
        "apaid": "2000",
        "ckdate": "2022-06-17",
        "bstatus": "confirm"        
    },
    {
        "id": "1",
        "room_no": "Room No 101",
        "status": "confirm",
        "created_at": "2021-10-27 17:41:05",
        "bid": "72",
        "rid": "1",
        "guest_name": "sad",
        "tariff": "2222",
        "apaid": "2222",
        "ckdate": "2022-07-29",
        "bstatus": "reserve"        
    },
    {
        "id": "1",
        "room_no": "Room No 101",
        "status": "confirm",
        "created_at": "2021-10-27 17:41:05",
        "bid": "73",
        "rid": "1",
        "guest_name": "abid",
        "tariff": "2500",
        "apaid": "2500",
        "ckdate": "2022-06-15",
        "bstatus": "checkout"        
    },
    {
        "id": "2",
        "room_no": "Room No 102",
        "status": "checkout",
        "created_at": "2021-10-27 17:41:05",
        "bid": null,
        "rid": "2",
        "guest_name": null,
        "tariff": null,
        "apaid": null,
        "ckdate": null,
        "bstatus": null        
    },
    {
        "id": "3",
        "room_no": "Room No 103",
        "status": "checkout",
        "created_at": "2021-10-27 17:41:05",
        "bid": null,
        "rid": "3",
        "guest_name": null,
        "tariff": null,
        "apaid": null,
        "ckdate": null,
        "bstatus": null        
    },
    {
        "id": "4",
        "room_no": "Room No 104",
        "status": "checkout",
        "created_at": "2021-10-27 17:41:05",
        "bid": null,
        "rid": "4",
        "guest_name": null,
        "tariff": null,
        "apaid": null,
        "ckdate": null,
        "bstatus": null        
    },
    {
        "id": "5",
        "room_no": "Room No 105",
        "status": "checkout",
        "created_at": "2021-10-27 17:41:05",
        "bid": null,
        "rid": "5",
        "guest_name": null,
        "tariff": null,
        "apaid": null,
        "ckdate": null,
        "bstatus": null        
    },
    {
        "id": "6",
        "room_no": "Room No 106",
        "status": "checkout",
        "created_at": "2021-10-27 17:41:06",
        "bid": null,
        "rid": "6",
        "guest_name": null,
        "tariff": null,
        "apaid": null,
        "ckdate": null,
        "bstatus": null        
    },
    {
        "id": "7",
        "room_no": "Room No 201",
        "status": "checkout",
        "created_at": "2021-10-27 17:41:06",
        "bid": null,
        "rid": "7",
        "guest_name": null,
        "tariff": null,
        "apaid": null,
        "ckdate": null,
        "bstatus": null        
    },
    {
        "id": "8",
        "room_no": "Room No 202",
        "status": "checkout",
        "created_at": "2021-10-27 17:41:06",
        "bid": null,
        "rid": "8",
        "guest_name": null,
        "tariff": null,
        "apaid": null,
        "ckdate": null,
        "bstatus": null        
    },
    {
        "id": "9",
        "room_no": "Room No 203",
        "status": "checkout",
        "created_at": "2021-10-27 17:41:06",
        "bid": null,
        "rid": "9",
        "guest_name": null,
        "tariff": null,
        "apaid": null,
        "ckdate": null,
        "bstatus": null        
    },
    {
        "id": "10",
        "room_no": "Room No 204",
        "status": "checkout",
        "created_at": "2021-10-27 17:41:06",
        "bid": null,
        "rid": "10",
        "guest_name": null,
        "tariff": null,
        "apaid": null,
        "ckdate": null,
        "bstatus": null        
    },
    {
        "id": "11",
        "room_no": "Room No 205",
        "status": "checkout",
        "created_at": "2021-10-27 17:41:06",
        "bid": null,
        "rid": "11",
        "guest_name": null,
        "tariff": null,
        "apaid": null,
        "ckdate": null,
        "bstatus": null        
    },
    {
        "id": "12",
        "room_no": "Room No 206",
        "status": "checkout",
        "created_at": "2021-10-27 17:41:06",
        "bid": null,
        "rid": "12",
        "guest_name": null,
        "tariff": null,
        "apaid": null,
        "ckdate": null,
        "bstatus": null        
    }
]

预期输出结果 #

[
    {
        "id": "1",
        "room_no": "Room No 101",
        "status": "confirm",
        "created_at": "2021-10-27 17:41:05",
        "bid": "70",
        "rid": "1",
        "guest_name": "test",
        "tariff": "2000",
        "apaid": "2000",
        "ckdate": "2022-06-17",
        "bstatus": "confirm"        
    },
    {
        "id": "2",
        "room_no": "Room No 102",
        "status": "checkout",
        "created_at": "2021-10-27 17:41:05",
        "bid": null,
        "rid": "2",
        "guest_name": null,
        "tariff": null,
        "apaid": null,
        "ckdate": null,
        "bstatus": null        
    },
    {
        "id": "3",
        "room_no": "Room No 103",
        "status": "checkout",
        "created_at": "2021-10-27 17:41:05",
        "bid": null,
        "rid": "3",
        "guest_name": null,
        "tariff": null,
        "apaid": null,
        "ckdate": null,
        "bstatus": null        
    },
    {
        "id": "4",
        "room_no": "Room No 104",
        "status": "checkout",
        "created_at": "2021-10-27 17:41:05",
        "bid": null,
        "rid": "4",
        "guest_name": null,
        "tariff": null,
        "apaid": null,
        "ckdate": null,
        "bstatus": null        
    },
    {
        "id": "5",
        "room_no": "Room No 105",
        "status": "checkout",
        "created_at": "2021-10-27 17:41:05",
        "bid": null,
        "rid": "5",
        "guest_name": null,
        "tariff": null,
        "apaid": null,
        "ckdate": null,
        "bstatus": null        
    },
    {
        "id": "6",
        "room_no": "Room No 106",
        "status": "checkout",
        "created_at": "2021-10-27 17:41:06",
        "bid": null,
        "rid": "6",
        "guest_name": null,
        "tariff": null,
        "apaid": null,
        "ckdate": null,
        "bstatus": null        
    },
    {
        "id": "7",
        "room_no": "Room No 201",
        "status": "checkout",
        "created_at": "2021-10-27 17:41:06",
        "bid": null,
        "rid": "7",
        "guest_name": null,
        "tariff": null,
        "apaid": null,
        "ckdate": null,
        "bstatus": null        
    },
    {
        "id": "8",
        "room_no": "Room No 202",
        "status": "checkout",
        "created_at": "2021-10-27 17:41:06",
        "bid": null,
        "rid": "8",
        "guest_name": null,
        "tariff": null,
        "apaid": null,
        "ckdate": null,
        "bstatus": null        
    },
    {
        "id": "9",
        "room_no": "Room No 203",
        "status": "checkout",
        "created_at": "2021-10-27 17:41:06",
        "bid": null,
        "rid": "9",
        "guest_name": null,
        "tariff": null,
        "apaid": null,
        "ckdate": null,
        "bstatus": null        
    },
    {
        "id": "10",
        "room_no": "Room No 204",
        "status": "checkout",
        "created_at": "2021-10-27 17:41:06",
        "bid": null,
        "rid": "10",
        "guest_name": null,
        "tariff": null,
        "apaid": null,
        "ckdate": null,
        "bstatus": null        
    },
    {
        "id": "11",
        "room_no": "Room No 205",
        "status": "checkout",
        "created_at": "2021-10-27 17:41:06",
        "bid": null,
        "rid": "11",
        "guest_name": null,
        "tariff": null,
        "apaid": null,
        "ckdate": null,
        "bstatus": null        
    },
    {
        "id": "12",
        "room_no": "Room No 206",
        "status": "checkout",
        "created_at": "2021-10-27 17:41:06",
        "bid": null,
        "rid": "12",
        "guest_name": null,
        "tariff": null,
        "apaid": null,
        "ckdate": null,
        "bstatus": null        
    }
]

原有代码问题 #

原有倒序遍历逻辑只实现了「同id只保留遍历到的第一条非排除项」，没有做状态优先级判断：倒序遍历id=1的条目时，最先碰到的是bstatus:checkout的条目，会被直接存入结果，后续遍历到优先级更高的bstatus:confirm条目时，因为id已经被标记过，会被直接跳过，最终保留的是低优先级数据，不符合要求。
原有实现代码如下：

for (var i = res.data.length - 1; i >= 0; i--) {
    if (index.indexOf(res.data[i].id) === -1) {
          if(res.data[i].bstatus !== 'reserve' && res.data[i].status !== 'cancel') {
            index.push(res.data[i].id);
            result.unshift(res.data[i]);
          }
    }
  }

正确实现代码 #

用Map按id存储条目，遍历过程中按优先级判断是否替换已存条目即可，代码如下：

const idMap = new Map();
// 第一步先过滤掉所有明确要排除的条目
const validItems = res.data.filter(item => {
    return item.bstatus !== 'reserve' && item.status !== 'cancel';
});

validItems.forEach(item => {
    const stored = idMap.get(item.id);
    // 同id无已存条目，直接存入
    if (!stored) {
        idMap.set(item.id, item);
        return;
    }
    // 已存条目不是最高优先级confirm，当前条目是confirm，替换为高优先级条目
    if (stored.bstatus !== 'confirm' && item.bstatus === 'confirm') {
        idMap.set(item.id, item);
    }
});

// 转为数组即为最终结果
const result = Array.from(idMap.values());

逻辑说明 #

• 先过滤无效条目减少后续遍历计算量
• 同id首次出现直接存入Map
• 同id重复出现时，只有当前条目优先级高于已存条目才做替换，保证最终每个id保留的是最高优先级的有效条目
• 运行后输出结果和预期完全一致。

内容的提问来源于stack exchange，提问作者Mohammed