Introduction
Data types actually defines what type of the data can be stored in a variable.
Types
Usually the data types can be categorized into 3 groups
- Value Data Types
- Pointer Data Types
- Reference Data Types
Value Data Types
The value data types are integer-based and floating-point based. C# language supports both signed and unsigned literals. There are 2 types of value data type in C# language.
- Predefined Data Types – such as Integer, Boolean, Float, etc.
- User defined Data Types – such as Structure, Enumerations, etc.
The memory size of data types may change according to 32 or 64 bit operating system. Let’s see the value data types. It size is given according to 32 bit OS.
| Data Types | Memory Size | Range |
|---|---|---|
| bool | 1 bit | 1 or 0 |
| char / signed char | 1 byte | -128 to 127 |
| unsigned char | 1 byte | 0 to 127 |
| short / signed short | 2 byte | -32,768 to 32,767 |
| unsigned short | 2 byte | 0 to 65,535 |
| int / signed int | 4 byte | -2,147,483,648 to -2,147,483,647 |
| unsigned int | 4 byte | 0 to 4,294,967,295 |
| long /signed long | 8 byte | -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807 |
| unsigned long | 8 byte | 0 – 18,446,744,073,709,551,615 |
| float | 4 byte | 1.5 * 10-45 – 3.4 * 1038, 7-digit precision |
| double | 8 byte | 5.0 * 10-324 – 1.7 * 10308, 15-digit precision |
| decimal | 16 byte | at least -7.9 * 1028 – 7.9 * 1028, with at least 28-digit precision |
Pointer Data Types
The pointer in C# language is a variable, it is also known as locator or indicator that points to an address of a value.
References Data Types
The reference data types do not contain the actual data stored in a variable, but they contain a reference to the variables. If the data is changed by one of the variables, the other variable automatically reflects this change in value.
There are 2 types of reference data type in C# language.
- Predefined Types – such as Objects, String.
- User defined Types – such as Classes, Interface.