C#Syntax

C# Syntax

In the previous chapter, we created a C# file called Program.cs, and we used the following code to print "Hello World" to the screen:

using System;namespace HelloWorld{  class Program  {    static void Main(string[] args)    {      Console.WriteLine("Hello World!");        }  }}

Example explained

Line 1:using System means that we can use classes from theSystem namespace.

Line 2: A blank line. C# ignores white space. However, multiple lines makes the code more readable.

Line 3:namespace is used to organize your code, and it is a container for classes and other namespaces.

Line 4: The curly braces{} marks the beginning and the end of a block of code.

Line 5:class is a container for data and methods, which brings functionality to your program. Every line of code that runs in C# must be inside a class. In our example, we named the class Program.

Line 7: Another thing that always appear in a C# program is theMain method. Any code inside its curly brackets{} will be executed.You don't have to understand the keywords before and after Main. You will get to know them bit by bit while reading this tutorial.

Line 9:Console is a class of theSystem namespace, which has aWriteLine() method that is used to output/print text. In our example, it will output "Hello World!".

If you omit theusing System line, you would have to writeSystem.Console.WriteLine() to print/output text.

Note: Every C# statement ends with a semicolon;.

Note: C# is case-sensitive; "MyClass" and "myclass" have different meaning.

Note: UnlikeJava, the name of the C# file does not have to match the class name, but they often do (for better organization).When saving the file, save it using a proper name and add ".cs" to the end of the filename. To run the example above on your computer, make sure that C# is properly installed: Go to theGet Started Chapter for how to install C#. The output should be: