Type casting in C#

 Data Type Casting:

The C# Type System contains two data types: Value Types (int, long, etc.), Reference Types (object, string etc.)

 

Sometimes it’s required to convert value type to reference type and vice versa.

 

i.                 Boxing:

àThe process of converting a Value Type variable (long, int etc.) to a Reference Type variable (object, string) is called Boxing.

 

àBoxing is an implicit conversion process means compiler internally convert data types.

àValue Type variables are always stored in Stack memory.

 

Example:

int num = 23; // value type

Object Obj = num; // Boxing

ii.              Unboxing:

àThe process of converting a Reference Type variable into a Value Type variable is known as Unboxing.

àIt is an explicit conversion process.

à Reference Type variables are always stored in Heap memory.

 

Example:

string str = “1”;    // reference type

int i = Convert.ToInt32(str);    // Unboxing

Boxing vs. Unboxing:

Boxing	Unboxing
Convert value type into an Reference type.	Convert an reference type into value type.
Boxing is an implicit conversion process.	Unboxing is the explicit conversion process.
Value stored on the stack memory.	Reference stored on the stack memory.

 

C# provides built-in methods for Type-Conversions as follows :

Method	Description
ToBoolean	It will converts a type to Boolean value
ToChar	It will converts a type to a character value
ToByte	It will converts a value to Byte Value
ToDecimal	It will converts a value to Decimal point value
ToDouble	It will converts a type to double data type
ToInt16	It will converts a type to 16-bit integer
ToInt32	It will converts a type to 32 bit integer
ToInt64	It will converts a type to 64 bit integer
ToString	It will converts a given type to string