Data Types and Variables
C# Data Types

Data types tell us a few things about a piece of data, like:

  • How it can be stored
  • What operations we can perform with it
  • Different methods it can be used with

Data types are present in all programming languages, but are particularly important in C#. That’s because C# is known as a strongly-typed language—it requires that the programmer specify the data type of every value and expression. While it means writing more code, using types has long term benefits like built-in documentation and increased readability.

As we can see to the diagram to the right, C# has several built-in data types. You don’t need to memorize all of them, but pay specific attention to these common ones that we’ll use throughout our lessons:

  • int - whole numbers, like: 1, -56, 948
  • double - decimal numbers, like: 239.43909, -660.01
  • char - single characters, like: “a”, “&”, “£”
  • string - string of characters, like: “dog”, “hello world”
  • bool - boolean values, like: true or false


Review the diagram to the right to see the difference between different C# data types and their usage. Continue when you’re ready.

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