Heap

Contrast with stack

• A place to store global variables.
• The heap is not automatically managed for you
• Data structure is hierarchical
• Variables need to be deallocated manually
• Garbage collection runs on the heap
• The heap is slower, but it can also store much more data than the stack
• In C, malloc and calloc are methods used to interact with the heap. Once memory has been allocated on the heap, we must use free() to deallocate that memory.
  • Failure to do this results in what’s called memory leaks.
• Pointers must be used to access memory on the heap
• allocating memory is done on the heap, not the stack (as with other variables)
• dynamic memory allocation can only be made through pointers and names (variable names) can't be given
  • malloc() is for allocating memory blocks from the heap in C

Heaps are used for dynamic memory allocation and unlike stacks, the program needs to look up the data in heap using pointers.

• Therefore it can store more data than a stack, but lookups take longer.

When we talk about "memory management" we are mostly talking about managing the Heap memory.

A heap is a tree structure

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Backlinks

• Memory
• Stack