試圖在蠟中創建誠實的NSDecimalNumber

Question

當我研究了我在Trying to create NSDecimal in iPhone-Wax面臨的問題時，我現在的目標要低得多。如何在Wax中創建功能完整的NSDecimalNumber？

我在AppDelegate.lua的頂部添加了以下兩行新鮮蠟項目。

local x = NSDecimalNumber:initWithString("2.3") 
print(x) 
print(x:class()) 

輸出是

(0x631e054 => 0x631d1a0) 2.3 
(0x631e924 => 0x25f618) NSCFNumber 

，而不是像

(0x621e834 => 0x620c550) <NSDecimalNumber: 0x620c550> 

打開完整記錄在蠟給在調試窗口下面的跟蹤：

Creating class for WaxServer(0x621bf40) 
Storing reference of class to userdata table WaxServer(0x621bf40 -> 0x621c454) 
Storing reference to strong userdata table WaxServer(0x621bf40 -> 0x621c454) 
Creating class for NSDecimalNumber(0x261120) 
Storing reference of class to userdata table NSDecimalNumber(0x261120 -> 0x6205e44) 
Storing reference to strong userdata table NSDecimalNumber(0x261120 -> 0x6205e44) 
Creating instance for NSDecimalNumberPlaceholder(0x6213450) 
Retaining instance for NSDecimalNumberPlaceholder(0x6213450 -> 0x621d7c4) 
Storing reference of instance to userdata table NSDecimalNumberPlaceholder(0x6213450 -> 0x621d7c4) 
Storing reference to strong userdata table NSDecimalNumberPlaceholder(0x6213450 -> 0x621d7c4) 
Creating instance for NSCFNumber(0x620c550) 
Retaining instance for NSCFNumber(0x620c550 -> 0x621e834) 
Storing reference of instance to userdata table NSCFNumber(0x620c550 -> 0x621e834) 
Storing reference to strong userdata table NSCFNumber(0x620c550 -> 0x621e834) 
(0x621e834 => 0x620c550) 2.3 
Creating class for AppDelegate(0x621ec50) 
: 
: 

有兩件事是在這個日誌中顯示了我沒有要求的NSDecimalNumberPlaceholder和NSCFNumber。我相信這些是我悲痛的根源，我不知道他們來自哪裏。任何想法如何解決這個問題？

最終我想調用方法decimalValue，但蠟抱怨說它不能調用一個數字的方法。

Answer 1

NSDecimalNumber覆蓋-description返回它表示的數字。當你正在記錄語句打印「2.3」時，它實際上正在打印NSDecimalNumber對象。您可以通過在x值上調用-class並自行驗證。