Fundamentals of C# Dot Net Datatypes

Hi all,

Hope you have better knowledge about dot net framework on my previous post Understanding Dot Net Framework. Now I am going to explain C# dot net datatypes. Ok, before start I want to explain some fundamentals of data. Of course many of you already know, anyway lets start.

In the above picture computer memory represents "A" as eight bits, I mean one byte. We all know

8 bit = 1 byte

So in this way we can represents up to 

2⁸ =256 characters. 

Here range for the characters are 0 -255. In C# we have a datatype byte, it's stored exactly 0 to 255 characters. In other words It's represents ASCII.

OK, Now if we want to represents more than 256 characters, what do we do? For this C# provide another datatype char, it's takes two bytes to represents a character. When we use this char datatype, we can represents up to,

2¹⁶ =65536

Here range for the characters are 0-65535. In other words, char datatype represents UNICODE. Series of char datatypes is called string. So we can categorize our data into three categories,

1. Alphanumeric
2. Numeric
3. Others

byte, char, string datatypes are represents Alphanumeric data. C# also having numeric datatypes. Lets we see what are all datatypes in c# using below diagram,

Below table represents min value and max value of each datatypes and what values it may have,

Category			Datatype	Range	Type of data
Alphanumeric			Byte	28 = 0 – 255	ASCII
			Char	216 = 0 – 65535	UNICODE
			String	Unlimited	Series of UNICODE
Numeric	Without Decimals	Signed numbers	Short / Int16	216 =  - 32768 to 32767	0 to 9
			Int / Int32	232	0 to 9
			Long/Int64	264	0 to 9
		Unsigned numbers	Ushort/ Uint16	216 = 0 to 65535	0 to 9
			Uint/Int32	232	0 to 9
			Ulong/Int64	264	0 to 9
	With Decimals		Float	Precision up to 7 decimals	0 to 9
			Double	Precision up to 16 decimals	0 to 9
			Decimal	Precision up to 32 decimals	0 to 9