Article Overview

  • Background
  • Difference between Stack and Heap Memory in C#
  • Summary

Background

Here is a list of the key differences between Stack and Heap Memory in C#. This is for both beginners and professional C# developers.

Stack vs heap

Difference between Stack and Heap Memory in C#

Category Stack Memory Heap Memory
What is Stack & Heap?

It is an array of memory.


It is a LIFO (Last In First Out) data structure.


In it data can be added to and deleted only from the top of it.

It is an area of memory where chunks are allocated to store certain kinds of data objects.

In it data can be stored and removed in any order.
How Memory is Manages? Stack Heap
Practical Scenario

Variable storing in stack

Value of variable storing in stack

Variable storing

Value of variable storing in heap

What goes on Stack & Heap?

"Things" declared with the following list of type declarations are Value Types

(because they are from System.ValueType):

bool, byte, char, decimal, double, enum, float, int, long, sbyte, short, struct, uint, ulong, ushort

"Things" declared with following list of type declarations are Reference Types

(and inherit from System.Object... except, of course, for object which is the System.Object object):

class, interface, delegate, object, string
Memory Allocation Memory allocation is Static Memory allocation is Dynamic
How is it Stored? It is stored Directly It is stored indirectly
Is Variable Resized? Variables can’t be Resized Variables can be Resized
Access Speed Its access is fast Its access is Slow
How is the Block Allocated?

Its block allocation is reserved in LIFO.

The most recently reserved block is always the next block to be freed.

 Its block allocation is free and done at any time
Visibility or Accessibility It can be visible/accessible only to the Owner of Thread It can be visible/accessible to all the threads
In Recursion Calls? In recursion calls memory fills up quickly In recursion calls memory filled up slowly
Used By? It can be used by one thread of execution It can be used by all the parts of the application
StackOverflowException .NET Runtime throws exception “StackOverflowException” when stack space is exhausted -
When wiped off?

Local variables get wiped off once they lose the scope

 -
Contains It contains values for Integral Types, Primitive Types and References to the Objects -
Garbage Collector -

It is a special thread created by .NET runtime to monitor allocations of heap space.

It only collects heap memory since objects are only created in heap


Summary

Now, I believe you will be able to know the key difference between Stack and Heap Memory in C#.

Stack and heap