[問題] 十三誡之七的疑問
問題(Question):
13誡之7有這一段:
錯誤例子:
unsigned int a = 0;
int b[10];
for(int i = 9 ; i >= a ; i--) { b[i] = 0; }
說明:由於 int 與 unsigned 共同運算的時候,會提升 int 為 unsigned,
因此迴圈條件永遠滿足,與預期行為不符
可是我昨天讀K&R第2版的時候,P43頁寫到:
Comparisons between signed and unsigned values are machine-dependent.
不過他舉的例子是long vs. unsigned int 和 long vs. unsigned long
我想問的是 int vs. unsigned int 的情況下是不是一定會把int升級為unsigned int?
感謝
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