Iterate through an optional array in Swift? - ios

Question

I'm using the cocoapod SQLite for this project like so
import SQLite
var db = try! Connection()
var id: Expression<Int>!
var identifier: Expression<String>!
With it I am reading a list of moves from a SQLite database.
Every monster has a moves that they can learn. Some monsters can learn more moves than others.
var monster: Monster!
var monArray = [Monster]()
var dataSource: DataSource!
To get the monsters move ID I use this code. This allows me to grab the first move in the array. Changing the 0 would get me the second, third move ect.
monster.moves![0]["move_id"] as! Int
Now I'm using the SQLite database because I need to match monster ID values in my plist with the ones in the SQLite database. I use this code to do so
override func viewWillAppear(_ animated: Bool) {
let movesArray = Array(try! db.prepare(Table("moves").where(identifier == moves.name!.lowercased())))
for user in movesArray {
monArray = dataSource.mons.filter{ $0.moves![0]["move_id"] as! Int == user[id] }
}
}
Everything works fine until I try to increase the index range.
for user in movesArray {
for i in 0...6 {
monArray = dataSource.mons.filter{ $0.moves![i]["move_id"] as! Int == user[id] }
}
}
See where I replace the 0 with the range i? I do that because since monsters have more than one move, if I leave it at 0 my app will only display the monsters that learn that move as their first move. To better explain, my current code does not look through whether the monster knows the move, it only looks through whether the monsters knows the move as its first move.
In the above code I increase the range thinking it would solve my issue, but my app will crash because some monsters only have 1 move in their index, so anything above index 0 will crash with the error
fatal error: Index out of range
So to recap, I need to iterate through the entire array instead of just the first index, without it crashing. How can I achieve this?

Answer 1

Without all the story arround your just asking how to iterate over an array like here
for item in array as type {
...
}

Answer 2

Your question seems to be more of a logical question. If I'm understanding what you have said, then each monster will have a minimum of 1 move, but not guaranteed to have more. So you would need to account for this.
Having a fixed limit like you do will certainly cause problems if not all monsters have that many moves as the array will not always be that size.
I would do something like:
let monsterMoveCount = user.moves.count
for i in 0...monsterMoveCount
// Do whatever logic here
Hopefully this helps!