初學者：與重複while循環和錯誤

Question

好了，所以不知道apple.stackexchange是這一個更好的地方，但我需要一些幫助，這代碼：

目的：要求用戶輸入的金額次循環應該重複。發送反饋，如果他們在錯誤的格式

問題鍵入它如果我在一個小數類型，只是把它作爲一個整數，仍然有效，我怎樣才能避免這種情況，或者檢查一下另一種方式？

set correctEntry to false --initially assume false 
repeat while correctEntry is false 
    --Let user put how many times it loops 
    set textToDisplay to "How often should this repeat?" 
    display dialog textToDisplay default answer "2.4" 
    set reps to text returned of the result 
    --Detailed check/feedback if they input wrong 
    try 
     --Begins as string, try making it an integer 
     set reps to reps as integer --coercion will should only work with integer 
     set correctEntry to true --remember won't get here if first statement fails 
    on error 
     try 
      --See if string can at least be converted to a number 
      set reps to reps as number 
      display dialog "Only integers" 
     on error 
      display dialog "That wasn't a number" 
     end try 
     -- still false here 
    end try 
end repeat 
--Only gets here if correctEntry becomes true 
repeat reps times 
    say "You entered right" 
end repeat 

此外，檢查是否輸入了負數，我只想用

if reps > 0 
    set reps to reps as integer 
    set correctEntry to true 
else 
    display dialog "Must be positive" 

有沒有更好的辦法？即使是建立在「積極」的電話？

最後，我使用http://www.fischer-bayern.de/as/as4as/AS4AS_e.pdf作爲教程，但我不確定它是否足夠好。我正在考慮去Mac OS X開發者庫，但希望有一些很好的學習方法。我只是有一點Perl的經驗，所以它不一定是一個完整的初學者。

更新：發現這個網站：http://www.macosxautomation.com/training/applescript/intro.html

非常感謝任何幫助，您可以提供。

Update2：如果我在第二個try塊中使用同一個整數檢查，那麼代碼將起作用，第一個錯誤是什麼。爲什麼它將一切都算作整數？更重要的是，爲什麼使用if語句提示如果放入我的腳本中不起作用？

Answer 1

嘗試......

repeat 
    set textToDisplay to "How often should this repeat?" 
    set reps to text returned of (display dialog textToDisplay default answer "2.4") 

    try 
     set reps to reps as number -- this makes sure no letters were entered 
     if (class of reps) is integer and reps is greater than 0 then 
      exit repeat 
     else 
      error "Only positive integers" 
     end if 
    on error theError number errorNumber 
     display dialog "There was an error: " & (errorNumber as text) & return & return & theError buttons {"OK"} default button 1 with icon stop 
    end try 
end repeat 

repeat reps times 
    say "You entered right" 
end repeat 

對於學習here's some tutorials。當我瞭解到我在「開始編寫腳本的教程」一節中完成了這些工作。隨着你越來越好，還有更高級的教程。最後，您還必須學習AppleScript編輯器中「幫助」菜單下的「AppleScript語言指南」。