Swift语言精要 - Dictionary(字典)

var states : Dictionary<String, String> = ["CA" : "California"]
var states : [String : String] = ["CA" : "California"]

var states = ["CA" : "California"]
var states = ["CA" : "California", "NV" : "Nevada", "OR": "Oregon", "AZ" : "Arizona"]

states["NV"] = "Nevada"

states.updateValue("State of Nevada", forKey: "NV")

let value = states["NV"]

states["TX"] = nil
// 或者
states.removeValueForKey("TX")

// iterate keys and values
for (key, value) in states {
    print("State name = \(value), abbreviation = \(key)")
}

// iterate keys
for abbreviation in states.keys {
    print("Abbreviation = \(abbreviation)")
}

// iterate values
for name in states.values {
    print("Name = \(name)")
}