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I reading a C book. but can't understand sentence that is
If the call calloc is successful, pointer of type void* that points to the base of the array in memory is returned;
Here, if pointer of type void* that points to the base of the array in memory, then array[0] has type of void??
I want know what is mean...
Thank you guys read my question I hope receive answer!
I can see how it's tempting to think that since int * points to int, then void * should point to void. But that's not the case. There's really no useful relationship between void * and void so it's best to think of them as separate concepts.
void * in C means a pointer that points to an object of unspecified type. You can think of it as the C analogue of Java Object if you're familiar with that.
void * has the following properties:
Any pointer type can be converted to and from void *, i.e. void * is large enough to hold any pointer, even on machines where pointers to different types can have different size.
Conversion between void * and other pointer types is implicit, you don't have to do an explicit cast.
It's not permitted to de-reference void *, i.e. we must cast it to a concrete pointer type before accessing the memory it points to.
You can't do address arithmetic on a void * in Standard C, though GCC allows you to do it as a documented extension.
void * is the type of choice for a function that needs to handle arbitrary data, like calloc().
calloc returns void* since:
calloc can be used to allocate memory for any type of object.void* can be implicitly cast to other pointer types.If you use:
void* ptr = calloc(...); it is valid but you can't use *ptr. A void* is not dereferenceable The pointer has to be cast to some other type to be dereferenced. E.g.
char* cptr = ptr; *cptr = 'a';