Memory allocation question ?

Question

What happens when we try to allocate memory after already allocating before once like ;
(1).
int *ptr=malloc(12);
ptr=malloc (18);

Or
(2).
int *ptr=malloc(12);
ptr=malloc (6);

Answer 1

It's called a memory leak.

The old data stay assigned to your program, yet they are unreachable and other programs won't be able to use that memory until your program terminates ( usually ).

https://en.wikipedia.org/wiki/Memory_leak

Answer 2

Thanks Dennis