In this chapter, we are going to find out what programming is in its core and how to write simple programs and apps.
- We will get familiar with the idea of programming languages and development platforms, along with concepts like compilation and code execution.
- We are going to look at the environments for software development (IDEs) and how to work with them, in particular with Visual Studio.
- We will write and execute our first program with the programming language C# in Visual Studio.
- We will exercise with a couple of tasks: we will create console-based programs, a graphical application (GUI) and a Web application.
- We will learn how to check the correctness of the solutions from this book in the Judge system of SoftUni.
- We will get to know some of the typical mistakes, which are often made during code writing and how to prevent doing them.
Watch a video lesson about what we shall learn in this chapter here: https://youtu.be/6RVKMlXtWg4.
Coding means to write commands for the computer, e.g.
Console.WriteLine("Welcome to coding");
Run the above code example: https://repl.it/@nakov/welcome-to-coding-csharp.
When executed, the above command prints the following text:
Welcome to coding
Several commands can be written as a sequence, called "computer program":
var size = 5; Console.WriteLine("Size = " + size); Console.WriteLine("Area = " + size * size);
Run the above code example: https://repl.it/@nakov/square-area-csharp.
The result (output) from the above program is as follows:
Size = 5 Area = 25
The above program (sequence of commands) consists of 3 commands:
- Defines a variable
sizeand stores an integer value
- Prints the value of the variable
a, along with some text.
- Calculates and prints the value of the expression
a * a.
Let's explain in greater detail what is programming, what is programing language, how to write commands and simple programs in the C# language, using the Visual Studio development environment.