Question

In C# the Main class has string[] args parameter.

What is that for and where does it get used?

Answer 1

From the C# programming guide on MSDN:

The parameter of the Main method is a String array that represents the command-line arguments

So, if I had a program (MyApp.exe) like this:

class Program {   static void Main(string[] args)   {     foreach (var arg in args)     {       Console.WriteLine(arg);     }   } }

That I started at the command line like this:

MyApp.exe Arg1 Arg2 Arg3

The Main method would be passed an array that contained three strings: ‘Arg1’, ‘Arg2’, ‘Arg3’.

If you need to pass an argument that contains a space then wrap it in quotes. For example:

MyApp.exe 'Arg 1' 'Arg 2' 'Arg 3'

Command line arguments commonly get used when you need to pass information to your application at runtime. For example if you were writing a program that copies a file from one location to another you would probably pass the two locations as command line arguments. For example:

Copy.exe C:\file1.txt C:\file2.txt