Remove object array duplicates and store non duplicate values in array

Question

I need to merge an array of deliveries that have notes, how would I remove the duplicate object but still keep the note string and store it in an array for the non duplicated object

Key begin the delivery number:

"data": [
        {
            "deliveryNumber": "0000001",
            "deliveryDate": "2021-10-01T00:00:00.000Z",
            "dateBeginProcess": null,
            "dateFinishedProcess": null,
            "status": "",
            "notes": "Note 1"
        },
        {
            "deliveryNumber": "0000001",
            "deliveryDate": "2021-10-01T00:00:00.000Z",
            "dateBeginProcess": null,
            "dateFinishedProcess": null,
            "status": "Ready",
            "notes": "Note 2"
        },
        {
            "deliveryNumber": "0000002",
            "deliveryDate": "2021-10-01T14:21:00.000Z",
            "dateBeginProcess": null,
            "dateFinishedProcess": null,
            "status": "Ready",
            "notes": null
        }
    ]

into

"data": [
        {
            "deliveryNumber": "0000001",
            "deliveryDate": "2021-10-01T00:00:00.000Z",
            "dateBeginProcess": null,
            "dateFinishedProcess": null,
            "status": "Ready",
            "notes": ["Note 1", "Note 2"]
        },
        {
            "deliveryNumber": "0000002",
            "deliveryDate": "2021-10-01T14:21:00.000Z",
            "dateBeginProcess": null,
            "dateFinishedProcess": null,
            "status": "Ready",
            "notes": null
        }
    ]

Welcome to Stack Overflow, please include your code attempt. — dariosicily, Oct 04 '21 at 16:04
Does this answer your question? [How to group an array of objects by key?](https://stackoverflow.com/questions/54177679/how-to-group-an-array-of-objects-by-key) — pilchard, Oct 04 '21 at 16:11
or this [Group array items using object](https://stackoverflow.com/questions/31688459/group-array-items-using-object) — pilchard, Oct 04 '21 at 16:22

score 1 · Accepted Answer · answered Oct 04 '21 at 16:34

You can use Array.prototype.forEach() to loop over the notes array. If a note is encountered twice add their notes together.

const notes = [
        {
            "deliveryNumber": "0000001",
            "deliveryDate": "2021-10-01T00:00:00.000Z",
            "dateBeginProcess": null,
            "dateFinishedProcess": null,
            "status": "",
            "notes": "Note 1"
        },
        {
            "deliveryNumber": "0000001",
            "deliveryDate": "2021-10-01T00:00:00.000Z",
            "dateBeginProcess": null,
            "dateFinishedProcess": null,
            "status": "Ready",
            "notes": "Note 2"
        },
        {
            "deliveryNumber": "0000002",
            "deliveryDate": "2021-10-01T14:21:00.000Z",
            "dateBeginProcess": null,
            "dateFinishedProcess": null,
            "status": "Ready",
            "notes": null
        }
    ]
    
    let filteredArray = []
    
    notes.forEach(note => {
      let noteFound = filteredArray.find(el => el.deliveryNumber === note.deliveryNumber)
      if(noteFound){
         // not first encounter
         // add notes together
         noteFound.notes.push(note.notes)
      }else{
         // first encounter
         // make notes an array
         note.notes = [note.notes||'']
         filteredArray.push(note)
      }
    })
    
    console.log(filteredArray)

Remove object array duplicates and store non duplicate values in array

1 Answers1