其中哪些是函數指針

Question

我在我的一個測驗中遇到了這個問題。

下面是哪些有效的函數指針聲明？選擇所有符合條件的。

A、void* f(int); 
B、int (*f)(); 
C、void (*f(int , void(*)(int)))(int); 
D、void (*(*f)(int))(); 

對我來說，我會選擇所有有一對括號的結尾。但我不知道C和D.

Answer 1

％的 「右左」 的規則上http://ieng9.ucsd.edu/~cs30x/rt_lt.rule.html

A、void* f(int); f is a function taking an int para that returns a pointer to void 
B、int (*f)(); f is a pointer to a function that takes no (as it's c++) para and returns int 
C、void (*f(int , void(*)(int)))(int); f is a function that takes an int and a function pointer as parameters, returning a pointer to a function that takes an int as para and returns void 
D、void (*(*f)(int))(); f is a pointer to a function that takes an int as para and returns a pointer to a function that take no para and returns void. 

所以B和d是你的答案