Does a garbage collector collect stack memory, heap memory, or both?

Question

I read lot of articles about garbage collection and almost all article tells about heap memory. so my question is "garbage collection collects stack memory or heap memory or both".

Answer 1

It collects heap memory. Usually, stack memory is collected automatically when the execution path reaches the end of the scope. e.g.:

void fun()
{
  int n; // reservation on the stack as part of the activation record
  ...
} // returning the stack pointer to where it was before entering the scope

In fact, in a language like C++, stack allocated variables are called auto variables.

Answer 2

Heap memory.

Garbage collection is a method of deallocating memory that isn't being used anymore. Sometimes the "isn't being used anymore" part is tricky. With the stack, as soon as a function returns, we can be confident (excepting programmer error) that the local variables aren't being used anymore, so they are deallocated automatically at that time in nearly every language/runtime.