[iOS] Enum

Objective-C

//NS_ENUM，定義狀態等普通枚舉
typedef NS_ENUM(NSUInteger, TTGState) {
    TTGStateOK = 0,
    TTGStateError,
    TTGStateUnknow
};

//NS_OPTIONS，定義選項
typedef NS_OPTIONS(NSUInteger, TTGDirection) {
    TTGDirectionNone = 0,
    TTGDirectionTop = 1 << 0,
    TTGDirectionLeft = 1 << 1,
    TTGDirectionRight = 1 << 2,
    TTGDirectionBottom = 1 << 3
};

參考
http://blog.csdn.net/annkie/article/details/9877643

Swift

//簡易定義:首字母大寫
enum Color {
    case blue
    case red
    case green
    case gray
    case white
    case black
}

//複雜定義
enum ColorWithDesc:String {
    case blue = "藍色"
    case red = "紅色"
    case green = "綠色"
    case gray = "灰色"
    case white = "白色"
    case black = "黑色"
}

參考
http://www.99ios.com/index.php/archives/3153/