Types

C# is a strongly typed language. Every variable must be defined by a type.

The following is a list of common types used in C#:

• string
• int
• long
• decimal
• double
• bool
• DateTime

Strings

The string type is used for text. The following code shows an example of use of the string variable.

string name = "Anil";
Console.WriteLine($"Hello {name}");

Output

Hello Anil

Integers

Integers (int) are used to represent whole numbers (e.g. 3, 5, etc.). The range for the int type is : -2,147,483,648 to 2,147,483,647.

The long type has a greater range : -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807

int x = 1;
int y = 3;
int sum = x + y;
Console.WriteLine($"Sum : {sum.ToString()}");

Output

Sum : 4

Decimal

The type : Decimal is used to represent decimal numbers (eg: 3.14) with a fixed number of decimal places. Note the letter ‘M’ to represent a decimal.

Decimal pi = 3.14M;
Console.WriteLine($"The value of pi is {pi}");

Output

The value of pi is 3.14

Double

The type : double is used to represent floating point numbers. Doubles require less memory than decimals but are less precise.

Double pi = 3.14159;
Console.WriteLine($"The value of pi is {pi}");

Output

The value of pi is 3.14159

Bool

The type : bool is used to represent true or false(Boolean) values.

bool b = true;
Console.WriteLine($"{b.ToString()}");

Output

True

DateTime

The type: DateTime is used to represent Date and Time.

DateTime now = DateTime.Now;
Console.WriteLine($"The current date and time is {now}");

Output

The current date and time is 1/27/2020 4:27:54 PM

Arrays

You can store multiple variables of the same type in an array data structure. You declare an array by specifying the type of its elements. Note the index starts from 0.

int[] numbers = { 3, 0, 4, 8, 2 };
int a = numbers[3];
Console.WriteLine($"The fourth number in the array is : {a.ToString()}");

Output

The fourth number in the array is : 8