Getting and Displaying Input/ Output

GETTING AND DISPLAYING INPUT/ OUTPUT

^Ø    The following programs show how the inputs to the program are provided interactively through keyboard during the program execution

Command Line Arguments

^Ø    The Main method is the entry point of a C# console application or windows application. (Libraries and services do not require a Main method as an entry point.). When the application is started, the Main method is the first method that is invoked.

^Ø    There can only be one entry point in a C# program. If you have more than one class that has a Main method, you must compile your program with the /main compiler option to specify which Main method to use as the entry point. For more information, see /main (C# Compiler Options).

class TestClass

{

static void Main(string[] args)

{

// Display the number of command line arguments: System.Console.WriteLine(args.Length);

}

}

Overview

^Ø    The Main method is the entry point of an .exe program; it is where the program control starts and ends.

^Ø    Main is declared inside a class or struct. Main must be static and it should not be publicThe enclosing class or struct is not required to be static.

^Ø    Main can either have a void or int return type.

^Ø    The Main method can be declared with or without a string[] parameter that contains command-line arguments. When using Visual Studio to create Windows Forms applications, you can add the parameter manually or else use the Environment class to obtain the command-line arguments. Parameters are read as zero-indexed command-line arguments.

^Ø    Unlike C and C++, the name of the program is not treated as the first command-line argument.

Using ReadLine method

Example:

using System;

class csharp

{

Public static void main()

{

Console.Write(―Enter here‖);

String disp=console.ReadLine();

Console.WriteLine(―Hello‖+disp);

}}

Write() – Display the information within line break

WriteLine() – Display the information with line break

+ operator – used as concatenation operator