Swift: Iterate and Compare Dictionary Item to Dictionary Items in Array - ios

Question

I need to compare an item in one array of dictionaries to all the items in another array of dictionaries and find out if the first item was in the second array at all.
For example, array1 has a dictionary with [{"name": "zach", "age": "twenty"}, {"name": "ben", "age": "fifteen"}, etc.] in it. Array2 is similar with [{"name" = "eli", "age": "fifteen"}, {"name" = "will", "age": "fifteen"}, etc.].
If zach isn't in array2, I want to add him to it. How can I take the items from the first array of dictionaries and compare them to all the items in the second array so that I'll know whether or not I should add it?

Answer 1

Dictionary doesn't have duplicate key. In your ex you are having name key twice with in the same Dictionary and it is not possible, but if you have array something like below.
let array1 = [["name": "zach"], ["name": "eli"], ["name": "ben"]]
var array2 = [["name": "eli"], ["name" : "will"]]
Then you can try something like to add zach and ben name in array2.
let array2Name = array2.flatMap({$0["name"]}) // ["eli", "will"]
array2 = array1.reduce(array2) { !array2Name.contains($1["name"] ?? "") ? $0 + [$1] : $0 }
print(array2)
Output
[["name": "eli"], ["name": "will"], ["name": "zach"], ["name": "ben"]]
Edit: You are facing this issue because you are having array with type [[String:Any]] and in question you are showing as array of type [[String:String]], so change above code like this will works for you.
let array2Name = array2.flatMap({$0["name"] as? String}) // ["eli", "will"]
array2 = array1.reduce(array2) { !array2Name.contains($1["name"] as? String ?? "") ? $0 + [$1] : $0 }
print(array2)

Answer 2

I'm guessing that your question may be more complicated, but Dictionary is Equatable based on its contents, which means that you can iterate over the first Array, and query the second Array, as to whether it contains the same Dictionary. Like this:
let array1 : [Dictionary<String, String>] = [["one" : "two"], ["three" : "four"]]
let array2 : [Dictionary<String, String>] = [["one" : "two"], ["three" : "five"]]
var doesContain = false
for dict in array1 {
if array2.contains(where: { $0 == dict} ) {
doesContain = true
}
}
print(doesContain) // Should be true in this case, because both arrays contain ["one" : "two"]; if they had no duplicates, doesContain would remain false

Answer 3

If I understood correctly, you want to have a new array of unique dictionaries. This is what I can suggest you:
let array1: [String] = [["name":"test1"], ["name":"test12"]].flatMap { $0["name"] }
let array2: [String] = [["name":"test1"], ["name":"test3"]].flatMap { $0["name"] }
let set = Set<String>(array1).union(Set<String>(array2))
let resultArrayOfDicts = set.map{ ["name": $0] }