Value Type & Reference Type

Value Type & Reference Type

Application memory is mainly divided into two memory component . Heap and Stack .

Heap is a separate area of memory for holding reusable objects .Actual object is allocated in Heap .A variable containing pointer to an object is allocated on stack , when call by stack actually return the memory address of the objects.

Value Type : Int/Bool/Struct /Enum

Reference Type :Class/array/interface/delegate

Value Type

• Value Type  are stored on stack
• Value Type  contains actual value
• Value Type  cannot contain null values.
• Value type is popped on its own from stack when they go out of scope.
• For Value Type  Memory is allocated at compile time

Reference Type

• Reference Type  are stored on heap
• Reference Type contains reference to a value
• Reference Type  can contain null values.
• Reference Type required garbage collector to free memory.
• Reference Type memory is allocated at run time

Stack

• very fast access
• local variables only
• variables cannot be resized
• It is a Last-in, First-out (LIFO) data structure
• Static memory allocation

Heap

• No limit on memory size
• Variables can be resized
• Fist in First Out
• Dynamic memory allocation

Example of Stack

 

 int a=100;

 string ="C# program”;

  int a=5+6;

Exaple of Heap 

class MyClass
{
    int myInt = 0;
    string myString = "Something";
}

class Program
{
    static void Main(string[] args)
    {
       MyClass m = new MyClass();
    }
}