如何在javascript（lodash）中替换对象数组中的对象

Question

I have following object array:

var arr = [
  {
    id    : "a1",
    guid  : "sdfsfd",
    ...
    value : "abc",
    status: false
  },
  {
    id    : "a2",
    guid  : "sdfsfd",
    ...
    value : "def",
    status: true
  },
  ...
]

I have this object:

var obj = {
  id      : "a1",
  guid    : "sdfsfd",
  ...
  value   : "xyz",
  status  :  true
}

I need to replace the object in the array with this object where the "id" is same. So the resulting array will be:

var arr = [
  {
    id    : "a1",
    guid  : "sdfsfd",
    ...
    value : "xyz",
    status: true
  },
  {
    id    : "a2",
    guid  : "sdfsfd",
    ...
    value : "def",
    status: true
  },
  ...
]

Additionally I need to add this object to the array if an object with that id doesn't exists.

How to achieve this using minimal lodash code? Looking for something like

arr = _.merge_by_key(arr,obj,"id");

Answer 1

you can do it with _.unionBy

var res = _.unionBy([obj], arr, 'id');

but check a note at this comment

Answer 2

You can use .findIndex()

var i = arr.findIndex(o => o.id === obj.id);
if (arr[i]) { arr[i] = obj } else { arr.push(obj) };

Answer 3

You can use _.findIndex with the _.matchesProperty shorthand:

var index = _.findIndex(arr, ['id', obj.id]);
arr[index >= 0 ? index : arr.length] = obj;

 var arr = [{ id: "a1", guid: "sdfsfd", value: "abc", status: false }, { id: "a2", guid: "sdfsfd", value: "def", status: true }]; var obj = { id : "a1", guid : "sdfsfd", value : "xyz", status : true }; var index = _.findIndex(arr, ['id', obj.id]); arr[index >= 0 ? index : arr.length] = obj; console.log(arr); 

 .as-console-wrapper { min-height: 100% !important; } 

 <script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.4/lodash.js"></script> 

Answer 4

Here's a lodash solution that uses keyBy to create an object wherein each item in the collection is represented by their id , set to override the new object or possibly add the new object and lastly values to get the array representation of the object.

var result = _(arr).keyBy('id').set(obj.id, obj).values().value();

 var arr = [ { id : "a1", guid : "sdfsfd", value : "abc", status: false }, { id : "a2", guid : "sdfsfd", value : "def", status: true } ]; var obj = { id : "a1", guid : "sdfsfd", value : "xyz", status : true } var result = _(arr).keyBy('id').set(obj.id, obj).values().value(); console.log(result); 

 body > div { min-height: 100%; top: 0; } 

 <script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.4/lodash.js"></script> 

Answer 5

you can loop and use 'splice' function:

var added = false;
for(var i=0;i<arr.length; i++){
   if(arr[i].id === obj.id){
        arr.splice(i,1,obj);
        added = true;
        break;
   }
}

if(!added) arr.push(obj);

EDIT: missed added condition