DEV Community

Kristina (Coding Mama)
Kristina (Coding Mama)

Posted on • Originally published at

C# For Beginners - Lesson 3: Data Types

At the end of this lesson, you should be able to answer the following:

  • What is a data type?
  • What are some of the commonly used data types in C#?

C# is a very meticulous language. Every piece of data it encounters must have a type.

The type of the data determines the set of values that it can have, and also which operations can be performed with it. Depending on the syntax, C# can sometimes infer the type of the data.

Remember our Hello, World program earlier? We needed to enclose the text Hello, World! in double quotes ("") for it to be a valid value. Enclosing the text in double quotes made that entire piece of data be of the string type.

C# has many built-in data types. Some types have a special keyword in C#. We'll learn where these keywords are used later.

Here is a subset of the basic types you will likely encounter:


The string type can contain text values. The text can have letters, numbers, and symbols.

The length of the string can range from a single character to a whole paragraph - it can even be empty. They need to be enclosed in double quotes.

C# keyword: string

"To you, 2000 years from now"
Enter fullscreen mode Exit fullscreen mode


The integer type can contain integer (whole number) values. Integers can have a negative value and can be written as-is.

C# keyword: int

Enter fullscreen mode Exit fullscreen mode


The boolean type has only two possible values, true or false. Booleans are used in conditional expressions (which we'll learn in another lesson.)

C# keyword: bool

Enter fullscreen mode Exit fullscreen mode


The character type can contain a single character. Characters can be letters, numbers, and symbols. They need to be enclosed in single quotes ('').

C# keyword: char

Enter fullscreen mode Exit fullscreen mode

Floating-Point Numeric

The floating-point numeric type can contain numbers with fractional values, represented in decimal format. Like integers, they can be written as-is.

C# keyword: double (short for double-precision floating-point)

Enter fullscreen mode Exit fullscreen mode

Console.WriteLine() doesn't just take string values. It can also print out values of other types.

Try printing out each example above by calling Console.WriteLine() and replacing the value in the round brackets.

// String
Console.WriteLine("To you, 2000 years from now");

// Integer

// Boolean

// Character

// Floating-Point Numeric
Enter fullscreen mode Exit fullscreen mode

Run the program - you should see the values in the console output.

Printing out different data types


What is the data type of each value below?

  1. "true"
  2. -24601
  3. false
  4. 1.38064852
  5. ' '


Try to come up with your own values for each data type! Replace the code above with your values to print them out.

Top comments (0)