If you are C program you probably know about
is awesome because it does not zero-initialise. If you are
new to C and finds this annoying, there is alwayscalloc`.
But C also has a valuable function that is missing in C++,
it extends or shrinks the allocation for a variable (memory address)
and only create a new allocation if it is required, which is often is not.
For C++ programmers, the good news is the
free is still supported. You do not have do it the C++ way, and I
recommend to always do it the C way (for arrays, not objects.)