的Objective-C，C多的平等跡象之一，如果

Question

我也寫了一個聲明

if (sample.value > shortAverage > shortWithoutFirstAverage > longAverage) { 

和預期sample.value> longAverage

但是，這並不工作，它可能發生的樣品。值< longAverage

(lldb) p (sample.value > shortAverage > shortWithoutFirstAverage > longAverage) 
(bool) $13 = true 
(lldb) p sample.value 
(double) $14 = 0.029 
(lldb) p longAverage 
(double) $15 = 0.032 
(lldb) p (sample.value > longAverage) 
(bool) $16 = false 
(lldb) p shortAverage 

其它值

(double) $17 = 0.029821 
(lldb) p shortWithoutFirstAverage 
(double) $18 = 0.029802 

它看起來是作爲

評估，如果（（sample.value> shortAverage）>（shortWithoutFirstAverage> longAverage））{

但如何實現if語句？所需，使其true（sample.value> shortAverage> shortWithoutFirstAverage> longAverage）

Answer 1

你不能像檢查這 -

表達

if (sample.value > shortAverage > shortWithoutFirstAverage > longAverage) 

使用 -

if ((shortWithoutFirstAverage > longAverage) && (shortAverage > shortWithoutFirstAverage) && (sample.value > shortAverage)) 

Answer 2

您不能在C語言和相關語言中鏈接這樣的二進制運算符，如>。

變化：

if (sample.value > shortAverage > shortWithoutFirstAverage > longAverage) { 

到：

if (sample.value > shortAverage && 
    shortAverage > shortWithoutFirstAverage && 
    shortWithoutFirstAverage > longAverage) { 

Answer 3

只要做到這一點這樣：

if ((sample.value > shortAverage) && (shortAverage > shortWithoutFirstAverage) && (shortWithoutFirstAverage > longAverage))