Question

I’m trying to declare an array of pointers of a struct some_struct in C

Can I do:

some_struct* arr[10];

instead of:

some_struct** arr=(some_struct**)malloc(10*sizeof(some_struct*));

And what’s the difference?

Answer 1

• The first one puts the array on the stack.
• The second one allocates it on the heap.

In the first case, the lifetime of the array is only the scope at which it is defined in.
When it falls out of scope, it will be freed automatically so you don’t have to do any clean up.

In the second case, the array lives beyond the scope where the pointer is declared. So you will need to manually free() it later to avoid a memory leak.