Difference Between Stack vs. Heap

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Main Difference

The difference between stack and heap is that stack is a data structure that follows last in first out method whereas heap is a data structure that follows no method and memory is allocated in random order.

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Stack vs. Heap

Data structures are one of the main and important concepts in computer science. There are many data structures, stack and heap are the most important data structures. The stack is a data structure that follows last in first out method whereas heap is a data structure that follows no method and memory is allocated in random order. Basically, stack and heap are used for memory allocation. There is a linear and sequential allocation of memory in stack whereas there is only dynamic memory allocation in a heap. Stack makes an ordered list, in this ordered list new item is added, and then existing elements are deleted. The element is deleted or removed from the top of the stack, top of the stack is known as TOS that is (top of the stack). Not only deletion but insertion also take place from the top of the stack. Stack follow last in first out method. Function calls are supported in the stack. There is stack frame in the stack that holds a collection of stack entries. When you call a function in the stack the stack frame is pushed into the stack. Heap is a data structure that follows no method and memory is allocated in random order. There are random assignment and deassigment of the memory in a heap. A pointer is used by assignment to request a process in heap. If we want to deallocate you need to send deallocation request that is similar to stack.

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Comparison Chart

BasisStackHeap
MeaningThe stack is a data structure that follows last in first out methodHeap is a data structure that follows no method and memory is allocated in random order.
Allocation and deallocationIn stack allocation and deallocation are automaticIn heap allocation and deallocation are manual
Access timeThe access time of stack is fasterThe access time of heap is slower
ImplementationImplementation of the stack is hardImplementation of the heap is easy.

What is Stack?

Stack makes an ordered list, in this ordered list new item is added, and then existing elements are deleted. The element is deleted or removed from the top of the stack, top of the stack is known as TOS that is (top of the stack). Not only deletion but insertion also take place from the top of the stack. Stack follow last in first out method. Function calls are supported in stack. There is stack frame in stack that hold collection of stack entries. When you call a function in stack the stack frame is pushed into the stack.

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Operations on stack

  • Push
  • Pop
  • Peek
  • Top
  • Is empty

What is Heap?

Heap is a data structure that follows no method and memory is allocated in random order. There are random assignment and deassigment of the memory in a heap. A pointer is used by assignment to request a process in a heap. If we want to deallocate you need to send deallocation request that is similar to stack.

Key Differences

  1. Stack is a data structure that follow last in first out method whereas Heap is a data structure that follow no method and memory is allocated in random order.
  2. In stack allocation and deallocation are automatic whereas in heap allocation and deallocation are manual
  1. The access time of stack is faster whereas Access time of heap is slower
  2. Implementation of the stack is hard whereas Implementation of the heap is easy.

Comparison Video