iOS --- 總結Swift中常用的全域函數和extension（持續更新中）

iOS --- 總結Swift中常用的全域函數和extension（持續更新中）

將iOS開發中常用的Swift全域函數和extension（因Swift中不能使用宏定義）整理如下。
而對於Objective-C，其宏定義總結請參考部落格iOS — 總結Objective-C中常用的宏定義（持續更新中）。

////  Global.swift////  useful global methods and extension for Chris Hu//import Foundationfunc isIPhone4() -> Bool {    return UIScreen.mainScreen().currentMode?.size == CGSizeMake(640, 960)}func isIPhone5() -> Bool {    return UIScreen.mainScreen().currentMode?.size == CGSizeMake(640, 1136)}func isIPhone6() -> Bool {    return UIScreen.mainScreen().currentMode?.size == CGSizeMake(750, 1334)}func isIPhone6Plus() -> Bool {    return UIScreen.mainScreen().currentMode?.size == CGSizeMake(1242, 2208)}func isIPhone6PlusBigMode() -> Bool {    return UIScreen.mainScreen().currentMode?.size == CGSizeMake(1125, 2001)}func currentLanguage() -> String {    return NSLocale.preferredLanguages().first!}func systemVersion() -> String {    return UIDevice.currentDevice().systemVersion}func appVersion() -> String {    return String(NSBundle.mainBundle().infoDictionary!["CFBundleShortVersionString"]!)}extension UIColor {    public convenience init(hexString: UInt32, alpha: CGFloat = 1.0) {        let red     = CGFloat((hexString & 0xFF0000) >> 16) / 255.0        let green   = CGFloat((hexString & 0x00FF00) >> 8 ) / 255.0        let blue    = CGFloat((hexString & 0x0000FF)      ) / 255.0        self.init(red: red, green: green, blue: blue, alpha: alpha)    }}extension UITableViewDataSource {    // return total rows in the tableView    func totalRows(tableView: UITableView) -> Int {        let totalSections = self.numberOfSectionsInTableView!(tableView) ?? 1        var section = 0, total = 0        while section < totalSections {            total += self.tableView(tableView, numberOfRowsInSection: section)            section++        }        return total    }}