When I allocate memory on the heap with malloc(), there might be garbage in that memory unless I use calloc() or memset() to zero it out. Is this the same situation for the stack, or can I safely assume anything I allocate on the stack won’t have garbage in it? Also, does this differ on different systems or OSes?

>Solution :

It is the same situation on the stack.

Unless you explicitly initialize the values of variables to zero or some other value, variables with automatic storage duration will have indeterminate values.