Swift - converting an array to struct - swift

Question

I have an array with a list of data as following Data = [City, ZipCode, gpsLat, gpsLong]
I am trying to convert in struct as follows
struct Location {
var zipCode: Double
var nameCity: String
var gpsLat: DOuble
var gpsLong: Double
}
I am using the for-in loop
var resultat :[Location] = []
for item in Data {
resultat.append(Location(zipCode: Data[item][0], City : Data[item][1], gpsLat : Data[item][2], gpsLong : Data[item][3]))
}
I got the message
Cannot convert value of type '[String]' to expected argument type 'Int'

Answer 1

As #Achu says, you should use item[0], not `Data[item][0]
A for ... in loop defines a new local variable that contains each element in your array.
So if you have an array:
let array = ["now", "is", "the", "time"]
Normally you would loop through the array like this:
for item in array {
print(item)
}
That is the recommended way to do it.
If you wanted to loop through the indexes, that code would look like this:
for index in array.indices {
let item = array[index]
print(item)
}
or this:
for index in 0..<array.count {
let item = array[index]
print(item)
}
Note that a third option would be to use the Array object's enumerated() method:
for (index, item) in array.enumerated() {
print("item at index \(index) = '\(item)'")
}
That would output
item at index 0 = 'now'
item at index 1 = 'is'
item at index 2 = 'the'
item at index 3 = 'time'
You could also write that loop as a forEach:
array.enumerated().forEach() { (index, item) in
print("item at index \(index) = '\(item)'")
}
All that said, your use-case doesn't really lend itself to loops. If your array only contains a single set of Location properties, you probably want:
if let zipCode = Data[0] as Double,
let nameCity = Data[1] as? String,
let gpsLat = Data[2] as? Double,
let gpsLong = Data[3] as? Double {
let location = Location(zipCode: zipCode,
nameCity: nameCity,
gpsLat: gpsLat,
gpsLong: gpsLong)
// Do something with the location we just created
}
(BTW, a Double is a bad way to store zipcodes. I would suggest using Ints or Strings. Ints work well unless you have a zip code with a leading zero, in which case the leading zero would be truncated.)