CREATING DICTIONARIES
var namesAndScores = ["Anna": 2, "Brian": 2, "Craig": 8, "Donna": 6]
print(namesAndScores)
// > ["Craig": 8, "Anna": 2, "Donna": 6, "Brian": 2]
namesAndScores = [:]
var pairs: [String: Int] = [:]
pairs.reserveCapacity(20)
ACCESSING VALUES
namesAndScores = ["Anna": 2, "Brian": 2, "Craig": 8, "Donna": 6]
// Restore the values
print(namesAndScores["Anna"])
// > Optional(2)
namesAndScores["Greg"] // nil
namesAndScores.isEmpty // false
namesAndScores.count // 4
Array(namesAndScores.keys) // ["Craig", "Anna", "Donna", "Brian"]
Array(namesAndScores.values) // [8, 2, 6, 2]
ADDING VALUES
var bobData = ["name": "Bob", "profession": "Card Player", "country": "USA"]
bobData.updateValue("CA", forKey: "state")
bobData["city"] = "San Francisco"
UPDATING VALUES
bobData.updateValue("Bobby", forKey: "name")
bobData["profession"] = "Mailman"
bobData.removeValue(forKey: "state")
bobData["city"] = nil
ITERATION
for (player, score) in namesAndScores {
print("(player) - (score)")
}
// > Craig - 8
// > Anna - 2
// > Donna - 6
// > Brian - 2
for player in namesAndScores.keys {
print("(player), ", terminator: "") // no newline
}
print("") // print one final newline
// > Craig, Anna, Donna, Brian,
Running Time
print("some string".hashValue)
// > -497521651836391849
print(1.hashValue)
// > 1
print(false.hashValue)
// > 0
