尝试在我的数组中放入 object 时，此过滤器函数不会删除旧的 object

Question

回购： https://github.com/leongaban/api-design-node/tree/master

我的邮递员collection: https://www.getpostman.com/collections/b5a03b07836ad34b7758

预计：

当前 "lion" 个字符：

[
    {
        "id": "1",
        "name": "Teemo",
        "pride": "LoL",
        "age": "1",
        "gender": "male"
    },
    {
        "id": "2",
        "name": "Nasus",
        "pride": "LoL",
        "age": "10",
        "gender": "male"
    }
]

PUT http://localhost:3000/lions/1

正文：

{
    "age": "1",
    "gender": "female",
    "name": "LuLu",
    "pride": "LoL"
}

应该return GET 所有狮子的这个新列表：

[
    {
        "id": "1",
        "name": "LuLu",
        "pride": "LoL",
        "age": "1",
        "gender": "female"
    },
    {
        "id": "2",
        "name": "Nasus",
        "pride": "LoL",
        "age": "10",
        "gender": "male"
    }
]

结果

[
    {
        "id": "2",
        "name": "Nasus",
        "pride": "2",
        "age": "2",
        "gender": "female"
    },
    {
        "0": { // <-- This should not be here
            "id": "1",
            "name": "Teemo",
            "pride": "1",
            "age": "1",
            "gender": "female"
        },
        "age": "1",
        "gender": "female",
        "name": "LuLu",
        "pride": "LoL"
    }
]

完整 server.js

const express = require('express')
const app = express()
const bodyParser = require('body-parser')
const path = require('path')
const port = 3000

app.use(express.static('client'))
app.use(bodyParser.urlencoded({ extended: true }))
app.use(bodyParser.json())

let lions = []
let id = 0

app.get('/lions', function(req, res) {
  console.log('GET lions:', lions)
  res.json(lions)
})

app.get('/lions/:id', function(req, res) {
  let lion = lions.filter((lion => lion.id === req.params.id))

  res.json(lion || {})
})

app.post('/lions', function(req, res) {
  id++
  const lion = Object.assign({ id: id.toString() }, req.body)
  lions.push(lion)

  res.json(lion)
});

app.put('/lions/:id', function(req, res) {
  const paramId = req.params.id
  const updated = req.body

  if (updated.id) {
    delete updated.id
  }

  const oldLion = lions.filter((lion => lion.id === paramId))

  if (!oldLion) {
    res.send()
  }

  const newLion = Object.assign(updated, oldLion)
  console.log('newLion', newLion)
  lions = lions.filter(lion => lion.id !== paramId)
  lions.push(newLion)

  res.json(newLion)
});

app.listen(port, () => console.log(`NODE RUNNING on port: ${port}`))

PUT 函数

app.put('/lions/:id', function(req, res) {
  const paramId = req.params.id
  const updated = req.body

  if (updated.id) {
    delete updated.id
  }

  // Here I find the oldLion to replace by id:
  const oldLion = lions.filter((lion => lion.id === paramId))

  if (!oldLion) {
    res.send()
  }

  // Here I create a new object for the new "lion":
  const newLion = Object.assign(updated, oldLion)
  console.log('newLion', newLion)

  // Here I filter out the old lion:
  lions = lions.filter(lion => lion.id !== paramId)

  // New lion is pushed in:
  lions.push(newLion)

  res.json(newLion)
});

Answer 1

app.put() 方法可能存在的一个潜在问题是，当您执行 const oldLion = lions.filter((lion => lion.id === paramId)) 时，您将得到 array 作为结果。检查 Array.filter() for more info about this. So, I believe you want to use Array.find() 而不是 filter() 因为稍后您要调用：

const newLion = Object.assign(updated, oldLion);

而且，如果 oldLion 是一个 array，numeric-properties 将被添加到 updated 对象，如下一个示例所示：

const updated = {somekey: "somevalue"};
console.log(Object.assign(updated, [{somekey: "updatedValue"}]));

.as-console {background-color:black !important; color:lime;}
.as-console-wrapper {max-height:100% !important; top:0;}

因此，正如您所提到的，这会生成您意想不到的结构：

[
  {
    "id": "2",
    "name": "Nasus",
    "pride": "2",
    "age": "2",
    "gender": "female"
  },
  {
    "0": { // <-- This should not be here
        "id": "1",
        "name": "Teemo",
        "pride": "1",
        "age": "1",
        "gender": "female"
    },
    "age": "1",
    "gender": "female",
    "name": "LuLu",
    "pride": "LoL"
  }
]

更新

但是，在阅读了您评论的其他修复程序并了解了您正在尝试做的事情之后，也许最好使用 Array.findIndex() 并像这样编写您的 put() 方法：

app.put('/lions/:id', function(req, res)
{
    const paramId = req.params.id;
    const updated = req.body;

    if (updated.id)
        delete updated.id;

    // Here I find the oldLion to replace by id:
    const oldLionIdx = lions.findIndex(lion => lion.id === paramId);

    if (oldLionIdx < 0)
       res.send();

    // Here I update the object with the new "lion" properties:
    const newLion = Object.assign(lions[oldLionIdx], updated);
    console.log('newLion', newLion);

    res.json(newLion);
});

尝试在我的数组中放入 object 时，此过滤器函数不会删除旧的 object

When trying to PUT an object in my Array, this filter function is not removing the old object

javascript

arrays

put

node.js

express

预计：

结果

完整 server.js

PUT 函数

更新