Console app arguments, how arguments are passed to Main method

Question

This would be question from c# beginner. When I create console application I get Main method with parameter args as array string. I do not understand how this method is called by system and how args are passed to the Main method. Maybe someone could explain? Is Main method are overridden of some kind of console class?

namespace ConsoleApplication1
{
    class Program
    {    
        static void Main(string[] args)
        {    
        }
    }
}

Solution 1

The Main method is the Entry point of your application. If you checkout via ildasm then

.method private hidebysig static void  Main(string[] args) cil managed
{
  .entrypoint

This is what helps in calling the method

The arguments are passed as say C:\AppName arg1 arg2 arg3

Solution 2

All answers are awesome and explained everything very well

but I just want to point out different way for passing args to main method

in visual studio

1. right click on Project then choose Properties
2. go to Debug tab then on the Start Options section provide the app with your args

like this image

and happy knowing secrets

Solution 3

The runtime splits the arguments given at the console at each space.

If you call

myApp.exe arg1 arg2 arg3

The Main Method gets an array of

var args = new string[] {"arg1","arg2","arg3"}

Solution 4

How is main called?

When you are using the console application template the code will be compiled requiring a method called Main in the startup object as Main is market as entry point to the application.

By default no startup object is specified in the project propery settings and the Program class will be used by default. You can change this in the project property under the "Build" tab if you wish.

Keep in mind that which ever object you assign to be the startup object must have a method named Main in it.

How are args passed to main method

The accepted format is MyConsoleApp.exe value01 value02 etc...

The application assigns each value after each space into a separate element of the parameter array.

Thus, MyConsoleApp.exe value01 value02 will mean your args paramter has 2 elements:

[0] = "value01"

[1] = "value02"

How you parse the input values and use them is up to you.

Hope this helped.

Additional Reading:

Creating Console Applications (Visual C#)

Command-Line Arguments (C# Programming Guide)

Solution 5

in visual studio you can also do like that to pass simply or avoiding from comandline argument

 static void Main(string[] args)
    {
        if (args == null)
        {
            Console.WriteLine("args is null"); // Check for null array
        }
        else
        {
            args=new string[2];
            args[0] = "welcome in";
            args[1] = "www.overflow.com";
            Console.Write("args length is ");
            Console.WriteLine(args.Length); // Write array length
            for (int i = 0; i < args.Length; i++) // Loop through array
            {
                string argument = args[i];
                Console.Write("args index ");
                Console.Write(i); // Write index
                Console.Write(" is [");
                Console.Write(argument); // Write string
                Console.WriteLine("]");
            }
        }

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