How do two Obj-array Filter drop the same item?

    var arr = [
        {
            id: 111,
            name: "aaa"
        },
        {
            id: 222,
            name: "bbb"
        },
        {
            id: 333,
            name: "ccc"
        }
    ]

    var arr1 = [
        {
            id: 111,
            name: "aaa"
        },
        {
            id: 222,
            name: "bbb"
        }
    ]

    
    //
    var arr2 = [{
        id: 333,
        name :"ccc"
    }]
Javascript
Mar.03,2021

should we consider that the same id is the same? Or is it an overall comparison? Of course, this thing is called key anyway, so let's assume id comparison.

introduce lodashjs , 

console.log(_.xorBy(arr1, arr, 'id'), "id")

if it is other key, such as overall comparison. So 

console.log(_.xorBy(arr1, arr, function(v){return JSON.stringify(v)}),'fun')

you can do this if there are no duplicate objects in an array, although it doesn't feel very efficient 

var copyArr = arr2.map(val => JSON.stringify(val))

arr1 = arr1.filter(obj => {
  let index = copyArr.indexOf(JSON.stringify(obj))
  
  if (index === -1) return true
  arr2.splice(index, 1)
  copyArr.splice(index, 1)

})

arr1.concat(arr2)

let intersection = arr1.filter (v = > arr2.includes (v))
arrays take intersection

you can try this:

take the complement of arr1 concat arr2 , that is, the non-intersection of the two. The rules after
is used to implement reusable functions. Just pass in the key collection to check. 



  function filter (arr1, arr2, rules) {
    return arr1.filter(item1 => !arr2.some(item2 => rules.every(key => item1[key] === item2[key])))
  }

  function build (arr1, arr2, rules) {
    return [].concat(filter(arr1, arr2, rules), filter(arr2, arr1, rules))
  }

  let result = build(arr1, arr2, ['id', 'name'])

  console.log(result)

Previous: Error while compiling vue-devtools

Next: The problem of Route Handoff in Vue

css mysql arrays josn react html typescript webpack npm sass R objective-c .net sql-server jquery python-3.x angularjs django angular excel regex iphone ajax linux xml pandas vba spring database wordpress string wpf xcode windows bash postgresql oracle multithreading eclipse list firebase algorithm macos forms image scala visual-studio azure bootstrap spring-boot react-native python-2.7 docker performance function winforms matlab powershell apache dataframe api sqlite numpy rest shell selenium flutter dart maven loops qt swing android-studio csv express file class tensorflow sorting codeigniter perl
© 2021 CodesHelper
Advertising Contact us About us
Menu