2015年7月7日 · A void pointer (void* ) is a pointer that has no associated data type with it. A void pointer can hold address of any type and can be typcasted to any type. For example: int a = 10; char b = 'x'; void *unused = &a; // void pointer holds address of int 'a' unused = &b; // void pointer holds address of char 'b' Yes, void* print_xs() has the return type of void pointer. In …

2012年4月8日 · The * after the float is used to form a type. Very often when referring to a pointer type in words people will say "star" after the type rather "pointer", eg. "malloc returns a void star". I've never heard anyone use "asterisk" to refer to a type. The * at the start is used to de-reference the pointer thereby accessing the value it points to (interpreted as a float due to the following …

2012年7月24日 · a void* is a pointer, but the type of what it points to is unspecified. When you pass a void pointer to a function you will need to know what its type was in order to cast it back to that correct type later in the function to use it.

2015年4月9日 · The problem I'm having is that, while it was easy enough to complete the first assignment (printing a line of 4 stars, then a line of 3, then a line of 2 , then a line of 1, then all that again in reverse order), I can't seem to figure out how to format the for loops to print the pattern starting with a line of 1 star, then a line of 2, then a ...

2012年7月10日 · What is an object of type void **? I did some Google searches and could only find information about void*, which is a pointer to a sort of catch all top level type, if I understood correctly.

2014年12月17日 · In C, a double star is a pointer to a pointer. There are a couple of reasons to do this. First is that the pointer might be to an array of pointers. Another reason would be to pass a pointer to a function, where the function modifies the pointer (similar to an "out" parameter in …

2015年7月15日 · The void (*)() is the type of a function that returns nothing and takes an unspecified number of parameters. /* | --------------------| Cast to a function pointer

Specifically, can it point to int/float etc.? What about objects like NSString and the like? Any examples will be greatly appreciated.

2016年8月5日 · Your function prototype should be void f(int, int x[][*]). When you give the first parameter a name, then there's no need for the *. The whole point of this feature is that you can use old fashioned function prototypes that don't name the parameters.

2015年6月11日 · I'm dealing with some code that uses an external library in which you can pass values to callbacks via a void* value. Unfortunately, the previous person working on this code decided to just pass integers to these callbacks by casting an integer to a void pointer ((void*)val).