How to modify the value of only one of the keyvalues in the json array of js and keep the others？-CodePudding

This is the data that needs to be processed

let test=[
  {
    "id": 28620,
    "name": "fenbi1",
    "dn": "chl"
  },
  {
    "id": 5941,
    "name": "fenbi2",
    "dn": "chl"
  },
  {
    "id": 5226,
    "name": "fenbi3",
    "dn": "chl"
  }]

The requirement is to change only dn to ch the changed value is

  let test=[
  {
    "id": 28620,
    "name": "fenbi1",
    "dn": "ch"
  },
  {
    "id": 5941,
    "name": "fenbi2",
    "dn": "ch"
  },
  {
    "id": 5226,
    "name": "fenbi3",
    "dn": "ch"
  }]

This is the method I used

  test=test.map((item)=>({
    'id':item.id,
    'name':item.name,
    'dn':'ch'
  }))

This approach works but is not elegant because just to change one value you have to write the others as well, is there a better way to implement this?

CodePudding user response：

Just a simple for loop might be better than map in this situation

let test=[
  {
    "id": 28620,
    "name": "fenbi1",
    "dn": "chl"
  },
  {
    "id": 5941,
    "name": "fenbi2",
    "dn": "chl"
  },
  {
    "id": 5226,
    "name": "fenbi3",
    "dn": "chl"
  }]

  for (let item of test) {
     item.dn = 'ch'
  }

  console.log(test)

CodePudding user response：

Use rest syntax to collect the properties other than dn, then spread them into the new object.

const test=[{id:28620,name:"fenbi1",dn:"chl"},{id:5941,name:"fenbi2",dn:"chl"},{id:5226,name:"fenbi3",dn:"chl"}];

const output = test.map(({ dn, ...rest }) => ({ dn: 'ch', ...rest }));
console.log(output);

CodePudding user response：

You can write code like this.

let test=[
   {
      "id": 28620,
      "name": "fenbi1",
      "dn": "chl"
   },
   {
      "id": 5941,
      "name": "fenbi2",
      "dn": "chl"
   },
   {
      "id": 5226,
      "name": "fenbi3",
      "dn": "chl"
   }]

Now use array.map()

const newArray = test.map(e => ({...e,dn:"ch"}));