c - Why type cast a void pointer?

Question

Being new to C, the only practical usage I have gotten out of void pointers is for versatile functions that may store different data types in a given pointer. Therefore I did not type-cast my pointer when doing memory allocation.

I have seen some code examples that sometimes use void pointers, but they get type-cast. Why is this useful? Why not directly create desired type of pointer instead of a void?

Answer 1

There are two reasons for casting a void pointer to another type in C.

1. If you want to access something being pointed to by the pointer ( *(int*)p = 42 )
2. If you are actually writing code in the common subset of C and C++, rather than "real" C. See also Do I cast the result of malloc?

The reason for 1 should be obvious. Number two is because C++ disallows the implicit conversion from void* to other types, while C allows it.