Getting nil after setting a value in Swift struct

Question

I'm not sure but after setting a value in struct I'm getting nil when trying to read the variable:

struct MainStruct : Decodable{
    var array : [InternalArray]?
}

struct InternalArray : Decodable{
    var firstName : String?
    var lastName : String?
    var Number : Int?
}



var testing: MainStruct?

testing?.array![0].firstName = "TEST"

print("test value \(testing?.array![0].firstName!)")

prints nil

Answer 1

First of all you are using too many optionals.

Three(!) issues:

1. Testing is not initialized.
2. InternalArray is not initialized.
3. You cannot access an array with index subscription if there is no item at given index (causes an exception).

---

struct MainStruct : Decodable {
    var array = [InternalArray]()
}

struct InternalArray : Decodable {
    var firstName : String?
    var lastName : String?
    var Number : Int?
}

var testing = MainStruct()
testing.array.append(InternalArray())
testing.array[0].firstName = "TEST"

print("test value \(testing.array[0].firstName!)")

Answer 2

You haven't initialised testing.

Answer 3

This should work

var testing: MainStruct? = MainStruct()
testing?.array = []
testing?.array!.append(InternalArray())
testing?.array![0].firstName = "TEST"