ios - 在swift 2中从对象和键数组创建字典

Question

我有键数组和对象数组，我想创建一个字典，键数组中索引 Y 处的每个键都引用对象数组中相同索引 Y 处的对象，即我想编写这样的代码，但在 Swift 2 中:

NSMutableDictionary *dictionary = [NSMutableDictionary dictionaryWithObjects:ObjectsArray forKeys:KeysArray];

Answer 1

let keys = [1,2,3,4]
let values = [10, 20, 30, 40]
assert(keys.count == values.count)

var dict:[Int:Int] = [:]
keys.enumerate().forEach { (i) -> () in
    dict[i.element] = values[i.index]
}
print(dict) // [2: 20, 3: 30, 1: 10, 4: 40]

或更实用和通用的方法

func foo<T:Hashable,U>(keys: Array<T>, values: Array<U>)->[T:U]? {
    guard keys.count == values.count else { return nil }
    var dict:[T:U] = [:]
    keys.enumerate().forEach { (i) -> () in
        dict[i.element] = values[i.index]
    }
    return dict
}

let d = foo(["a","b"],values:[1,2])    // ["b": 2, "a": 1]
let dn = foo(["a","b"],values:[1,2,3]) // nil