Swift - Types, Equality, Conversion and All That Jazz: Serious types(function(return), optional(?, nil), array(index, out of range), dictionary(nil))

The Swift Programming Language
Apple Inc.

開発環境

• OS X Mavericks - Apple(OS)
• Xcode 6.0 Beta
• Swift (プログラミング言語)

Head First JavaScript Programming (Eric T. Freeman (著)、 Elisabeth Robson (著)、 O'Reilly Media )のChapter 7(Types, Equality, Conversion and All That Jazz: Serious types))、WHO AM I?(p.267)をSwiftで考えてみる。

WHO AM I?(p.267)

コード(Xcode)

main.swift

//
//  main.swift
//  sample267
//
//  Created by kamimura on 8/21/14.
//  Copyright (c) 2014 kamimura. All rights reserved.
//

import Foundation

func f() {}

var a:AnyObject
var b:AnyObject?
let c = [1,2]
var d = [1,2]
let e = ["a":1, "b":2]
var g = ["a":1, "b":2]

println(f())
// println(a) 
println(b)
// println(c[2]) out of range
// println(d[2]) out of range
// d[100] = 10 out of range
println(e["c"])
println(g["c"])
// g["c"]
g["c"] = 3
println(g)

入出力結果(Console Output)

nil
nil
nil
[c: 3, a: 1, b: 2]
Program ended with exit code: 0