What is a variable in C#?
A variable represents a string or a numeric value or an object of a class.
The value of that variable store may change but the name stays the same.
A variable is one type of field.
Example of variable change the value but the name remains the same.
int x = 1; //x holds the value 1
x =2; //now x holds the value 2
Strongly type and location
C# is a strongly typed language which means that you have to specify the type of the variable.
also, Each type in c# has a different size and layout in the memory.
also, Each type in c# has a different size and layout in the memory.
What is meant by reference type in C#?
There is two kind of types, one type is reference and value type.
reference type store reference to their data and value type point directly to the data.
also, two reference type can refer to the same object, there for a variable can affect on the object.
but with a value type, each variable has its own copy of data.
also, two reference type can refer to the same object, there for a variable can affect on the object.
but with a value type, each variable has its own copy of data.
Example of reference type
- Class
- Interface
- Delegate
C# also provides a built-in reference type
- Dynamic
- object
- string
Value Type
The variable will point directly to the location of the storage.
Example of Value Type
| Type | Represents | Range | Default Value |
|---|---|---|---|
| bool | Boolean value | True or False | False |
| byte | 8-bit unsigned integer | 0 to 255 | 0 |
| char | 16-bit Unicode character | U +0000 to U +ffff | '\0' |
| decimal | 128-bit precise decimal values with 28-29 significant digits | (-7.9 x 1028 to 7.9 x 1028) / 100 to 28 | 0.0M |
| double | 64-bit double-precision floating point type | (+/-)5.0 x 10-324 to (+/-)1.7 x 10308 | 0.0D |
| float | 32-bit single-precision floating point type | -3.4 x 1038 to + 3.4 x 1038 | 0.0F |
| int | 32-bit signed integer type | -2,147,483,648 to 2,147,483,647 | 0 |
| long | 64-bit signed integer type | -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807 | 0L |
| sbyte | 8-bit signed integer type | -128 to 127 | 0 |
| short | 16-bit signed integer type | -32,768 to 32,767 | 0 |
| uint | 32-bit unsigned integer type | 0 to 4,294,967,295 | 0 |
| ulong | 64-bit unsigned integer type | 0 to 18,446,744,073,709,551,615 | 0 |
| ushort | 16-bit unsigned integer type | 0 to 65,535 | 0 |
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