I need to merge two arrays of objects based on a common field, keeping the objects that are present in both arrays and combining their fields.

I am getting duplicate keys after merging two arrays. How to remove duplicate keys in JSON?

DW Script

%dw 2.0
import * from dw::core::Arrays

output application/json
var array1 = [
  { "id": 1, "name": "John" },
  { "id": 2, "name": "Jane" }
]

var array2 = [
  { "id": 1, "age": 30 },
  { "id": 3, "age": 25 },
  { "id": 2, "age": 25 }
]

var mergeArray = array1 map((item) ->
    array2 filter((item2, index) -> (item2.id == item.id)) map (item2) -> 
        (item2 ++ item)
)
---
flatten(mergeArray)

Output – Getting duplicate id

[
  {
    "id": 1,
    "age": 30,
    "id": 1,
    "name": "John"
  },
  {
    "id": 2,
    "age": 25,
    "id": 2,
    "name": "Jane"
  }
]