Topics
Introduction
C# Data types are categorized into following three types.
1. Values Types
Values types are actual data that directly contain their data & allocated on stack. Values types derived from class ‘System.ValueType’
| # | Datatype | Represents | Range | Default Value | .Net Class |
|---|---|---|---|---|---|
| 1 | bool | Boolean Value | True(1) or False(0) | False(0) | Boolean |
| 2 | byte | 8-bit unsigned integer | 0 to 255 | 0 | Byte |
| 3 | char | 16-bit Unicode character | U +0000 to U +ffff | ‘\0’ | Char |
| 4 | decimal | 128-bit precise decimal values with 28-29 significant digits | ±1.0 × 10e−28 to ±7.9 × 10e28 | 0.0M | Decimal |
| 5 | float | 32-bit single-precision floating point type | -3.402823e38 to 3.402823e38 | 0.0F | Single |
| 6 | double | 64-bit double-precision floating point type | -1.79769313486232e308 to 1.79769313486232e308 | 0.0D | Double |
| 7 | int | 32-bit signed integer type | -2,147,483,648 to 2,147,483,647 | 0 | Int32 |
| 8 | long | 64-bit signed integer type | -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807 | 0L | Int64 |
| 9 | sbyte | 8-bit signed integer type | -128 to 127 | 0 | Byte |
| 10 | short | 16-bit signed integer type | -32,768 to 32,767 | 0 | Int16 |
| 11 | ushort | 16-bit unsigned integer type | 0 to 65,535 | 0 | Uint16 |
| 12 | uint | 32-bit unsigned integer type | 0 to 4,294,967,295 | 0 | Uint32 |
| 13 | ulong | 64-bit unsigned integer type | 0 to 18,446,744,073,709,551,615 | 0 | Uint64 |
2. Reference Types
Reference type contain address of the memory where the data is store. 2 variables can reference to the same object so that operation on one variable can affect the object referenced by the other variable.
List of reference type in C# :
- Class : Basically class describe all attributes of of objects as well as the method that implement the behavior of member object. Class contain data and behavior of an entity. Classes are declared using the keyword class, as shown in the following example.
class Student { // properties, Methods,fields, events, delegates // and nested classes go here. } - Object : Object is a basic unit of a system. It is an instance of class. An Object is an entity that has behavior, attributes and identity. Attributes and behavior of an object are defined by class definition.
- String : String use to assign any type of value to the variable. string is an alias for String in the .NET Framework
string a = "good " + "morning";
3. Pointer Types
It store the memory address of another type.
char* a; int* b;