Swift Programming - Switch statement
Swift 的 Switch statement 和 Objective-C 有以下幾點差異
1. 語法定義：
從語法上可以看到,我們不必在每個case statement 後加上break, Swift 會自動結束switch case 區段.
2. 從上面語法定義可以發現, Switch 增加 "where" 關鍵字,它(where condition)提供額外的條件敘述來加強case, 使case 條件更加嚴謹.
例如：
case (let x, let y) where ( x == y )
3. 每個 case block 必須至少一個 statement, 如果真的沒有要執行的程式碼,那就請加上"break"吧.
The scope of each case can not be empty. As a result, you must include at least one statement following the colon (:) of each case label. Use a single break statement if you don’t intend to execute any code in the body of a matched case
資料來源: Apple, The Swift Programming Language
