Data Types & Type Conversions in C#

Data Type:

Data type is derived from System.ValueType. The value type contains some data. So, before declaring a variable we write the type of the variable and it is called datatype. According to these datatypesthe system allocates memory to the variables. The types of datatypes are:

Data Type	Allocated memory	Range
int	4 byte	-2,147,483,648 to 2,147,483,647
short	2 byte	-32,768 to 32,767
long	8 byte	-9,223,372,036,854,775,808 to 9,223,372,036,854,775,807
uint	4 byte	0 to 4,294,967,295
ushort	2 byte	0 to 65,535
ulong	8 byte	0 to 18,446,744,073,709,551,615
float	4 byte	-3.4 x 1038 to + 3.4 x 1038
double	8 byte	(+/-)5.0 x 10-324 to (+/-)1.7 x 10308
decimal	16 byte	(-7.9 x 1028 to 7.9 x 1028) / 100 to 28
byte	1 byte	0 to 255
sbyte	1 byte	-128 to 127
char	16-bit Unicode character	U +0000 to U +ffff
string	A string of Unicode characters.
bool	1 byte	True or false

Examples of data types:

• int a=23; //Allocated 4 bytes
• float c= 3.45; //Allocated 4 bytes
• decimal d=0.555555555; // Allocated 16 bytes
• bool h= true;
• char c =’A’;
• string greetings =”Hi all”;
• double = 4.33333365; // Allocated 8 bytes
• short = 2; // Allocated 2 bytes

Type Conversion:

Data type can be converted into similar types. And this conversion is called casting. It is of two types. They are:

1. Implicit casting:
   
   Data types can be converted implicitly as well as explicitly. Implicitly, the conversion is done by the compiler but there is threat of losing data. It is also called implicit casting. In implicit casting, no external cast function is written.
   
   Example:
   
   Int x;
   Double y= x;
   
   Here, x is integer in start but it is changed into double without writing any casting function.
   
   
2. Explicit casting:
   
   Explicitly, the conversion is done by using casting to avoid threat of losing data. In explicit casting, external predefined function is written. They need a cast operator.
   
   Example:
   
   double y = 123;
   int x = (int)y;
   
   Here, y is double in start but it is explicitly changed into integer by writing cast function.
   

There are different type Conversion methods. They are,

1	ToBoolean	Converts a type to a Boolean value, where possible.
2	ToByte	Converts a type to a byte.
3	ToChar	Converts a type to a single Unicode character, where possible.
4	ToDateTime	Converts a type (integer or string type) to date-time structures.
5	ToDecimal	Converts a floating point or integer type to a decimal type.
6	ToDouble	Converts a type to a double type.
7	ToInt16	Converts a type to a 16-bit integer.
8	ToInt32	Converts a type to a 32-bit integer.
9	ToInt64	Converts a type to a 64-bit integer.
10	ToSbyte	Converts a type to a signed byte type.
11	ToSingle	Converts a type to a small floating point number.
12	ToString	Converts a type to a string.
13	ToType	Converts a type to a specified type.
14	ToUInt16	Converts a type to an unsigned int type.
15	ToUInt32	Converts a type to an unsigned long type.
16	ToUInt64	Converts a type to an unsigned big integer.

Example:

using System;
namespace TypeConversionApplication
{
      class StringConversion
    {
         static void Main(string[] args)
         {
             int i = 5;
            float f = 53.0 f;
            double d = 235.75442;
            bool b = true;
            Console.WriteLine(i.ToString());
            Console.WriteLine(f.ToString());
            Console.WriteLine(d.ToString());
            Console.WriteLine(b.ToString());
            Console.ReadKey();
        }
    }
}

After execution the output generated will be:

5
53.0
235.75442
True

I hope this blog will help you in learning data types and their conversion. Please do comment and give your valuable feedback if needed.