Swift - Liberated functions: First Class Functions(isOrderedBefore(comparison function))

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 10(Liberated functions: First Class Functions)、SHARPEN YOUR PSENCIL(p.459)をSwiftで考えてみる。

SHARPEN YOUR PSENCIL(p.459)

コード(Xcode)

main.swift

//
//  main.swift
//  sample459
//
//  Created by kamimura on 9/13/14.
//  Copyright (c) 2014 kamimura. All rights reserved.
//

import Foundation

func compareNumbers(num1:Int, num2:Int) -> Bool {
    return num1 - num2 < 0
}

for x in 1...5 {
    for y in 1...5 {
        println("\(x) \(y) \(compareNumbers(x, y))")
    }
}

入出力結果(Console Output)

1 1 false
1 2 true
1 3 true
1 4 true
1 5 true
2 1 false
2 2 false
2 3 true
2 4 true
2 5 true
3 1 false
3 2 false
3 3 false
3 4 true
3 5 true
4 1 false
4 2 false
4 3 false
4 4 false
4 5 true
5 1 false
5 2 false
5 3 false
5 4 false
5 5 false
Program ended with exit code: 0