Showing posts with label reference types. Show all posts
Showing posts with label reference types. Show all posts

Saturday 19 September 2015

Value Types Vs Reference Types Dotnet


Stack and heap

In order to understand stack and heap, let’s understand what actually happens in the below code internally.

public void Method1()
{
    // Line 1
    int i=4;

    // Line 2
    int y=2;

    //Line 3
    class1 cls1 = new class1();
}


It’s a three line code, let’s understand line by line how things execute internally.
  • Line 1: When this line is executed, the compiler allocates a small amount of memory in the stack. The stack is responsible for keeping track of the running memory needed in your application.
  • Line 2: Now the execution moves to the next step. As the name says stack, it stacks this memory allocation on top of the first memory allocation. You can think about stack as a series of compartments or boxes put on top of each other.
  • Memory allocation and de-allocation is done using LIFO (Last In First Out) logic. In other words memory is allocated and de-allocated at only one end of the memory, i.e., top of the stack.
  • Line 3: In line 3, we have created an object. When this line is executed it creates a pointer on the stack and the actual object is stored in a different type of memory location called ‘Heap’. ‘Heap’ does not track running memory, it’s just a pile of objects which can be reached at any moment of time. Heap is used for dynamic memory allocation.