Deleting element from array dynamically and reducing the size of the array

It's easy in C++ if you use a std::vector instead of a plain array.

#include <vector>
#include <algorithm>
// this isn't a complete program you could compile, just a code snippet
std::vector<int> myvec(10);
// let's pretend myvec has been filled with suitable values, to remove any
// twelves:
myvec.erase(std::remove(myvec.begin(), myvec.end(), 12), myvec.end);

If you really don't want to use std::vector, for POD types[^] you can use realloc[^] to resize the array after removing an element.

Of course, under the hood realloc is often copying the array and invokes pretty much the same "magic" as vector, so I don't know what you would really achieve with it, but it is an option.

The answers provided by Richard and markkuk are correct.

I don't know what you mean with "Array".
- If you want to modify the size of a fixed size buffer, then this is not possible.
- If you want to change the size of a dynamic allocated buffer allocated with malloc or calloc, then you can use realloc. Note that the resuling pointer will probably be different from the original one.
- If you want to change the size of a dynamic allocated buffer allocated with new, then you can write your own realloc function using new.

But as the others already told you, I suggest you use STL instead of realloc.