Swift 3 - Difference between two arrays of dictionary

Question

I have two arrays of dictionaries:

let arrayA = [["name1": "email1"], ["name2": "email2"]]
let arrayB = [["name1": "email1"], ["name3": "email3"]]

I want to compare them and get another two arrays: arrayC should have the elements in arrayA but not in arrayB, and arrayD should have the elements in arrayB but not in arrayA:

let arrayC = [["name2": "email2"]]
let arrayD = [["name3": "email3"]]

How can I do this taking into the consideration large arrays?

Answer 1

Here you go

let arrayA = [["name1": "email1"], ["name2": "email2"]]
let arrayB = [["name1": "email1"], ["name3": "email3"]]

let arrayC = arrayA.filter{
    let dict = $0
    return !arrayB.contains{ dict == $0 }
}

let arrayD = arrayB.filter{
    let dict = $0
    return !arrayA.contains{ dict == $0 }
}