⦁ Namespace declaration
⦁ A class
⦁ Class methods
⦁ Class attributes
⦁ A Main method
⦁ Statements and Expressions
Let us look at a simple code given below which is printed the words "Hello World" −
static void Main(string args)
/* my first program in C# */
Let's look at the different parts of the given program -
using keyword is used to include the System namespace in the program and program generally has multiple using statements also.
A namespace is a collection of classes.The "HelloWord" namespace contains the class HelloWorldClass.
The class HelloWorldClass contains the method and data which is definitions that your program uses.Classes are generally contain multiple methods.Methods define the behavior of the class.Whatever, the HelloWorldClass class has only one method Main.
The Main Method entry point for all C# programs.The Main method states what the class does when executed.
This is ignor by the compiler and also it is put to add comments in the program.
In the statement, Main method specifies its behavior .
WriteLine is a Method and the Console class defined under the System namespace.This Console.WriteLine statement display
on the screen.
The last line Is Console.ReadKey();
This Console.ReadKey() method makes the program wait for a key press and it prevents the screen from running and closing quickly when the program is launched from Visual Studio .NET.
Some important points in C# given below
⦁ C# is case sensitive.
⦁ You must end with a a semicolon (;) in all statements and expression
⦁ The program execution starts at the Main method.
⦁ Program file name could be different unlike java in the class name.
Compiling and Executing the Program
If you are using asp.net compiling and executing C# programs,Some takes given steps −
⦁ Start Visual Studio.
⦁ Go to menu bar, choose File ->> New ->> Project.
⦁ Choose Visual C# from templates, and then choose Windows.
⦁ Choose Console Application.
⦁ Specify a name for your project and click OK button.
⦁ This creates a new project in Solution Explorer.
⦁ Write code in the Code Editor.
⦁ Click the Run button or you can also press F5 key to execute the project. Then you can see Hello Word on your windows screen.
You can compile the C # program using the command-line instead of the Visual Studio IDE -
⦁ Open a text editor and add the above-mentioned code.
⦁ Save the file as helloworld.cs
⦁ Open the command prompt tool and go to the directory where you saved the file.
⦁ Compile your code to type csc helloworld.cs and press enter.
⦁ The command prompt takes you to the next line and generates helloworld.exe executable file when there are no errors in your code.
⦁ Type helloworld to execute your program.
⦁ You can see the output Hello World printed on the screen.