     using System;
    
    namespace HelloWorld
    {
      public static class static_extensions {
    	  public static void print(this object item, int data = 0) {
          Console.WriteLine("EXT: I AM A STATIC EXTENSION!");
          Console.WriteLine("EXT: MY ITEM IS: " + item);
          Console.WriteLine("EXT: MY DATA IS: " + data);
          string i;
          if (item == null) {
            i = "null";
          } else {
            i = item.GetType().Name;
          }
          Console.WriteLine("EXT: MY TYPE IS: " + i + "\n");
        }
      }
    
    	public class Program
    	{
        
    		public static void Main(string[] args)
    		{
    		  // an extension method can be
    		  //   called directly
    		  //  (null is an instance)
    		  static_extensions.print(null);
    
    		  // an extension method can also be
    		  //   called directly with arguments
    		  //  (null is an instance)
    		  static_extensions.print(null, 1);
    		  
    		  // an extension method can also be
    		  //   called as part of an instance
    		  int x = 0; // initialize int
    		  x.print();
    		  
    		  // an extension method can also be
    		  //   called as part of an instance
    		  //   and with data
    		  int x2 = 0; // initialize int
    		  x2.print(2);
    		  
    		  // an extension method can also be
    		  //   called directly from null
    		  //   since `null` is an instance
    		  ((string)null).print();
    		  
    		  // an extension method can also be
    		  //   called directly from null
    		  //   and with data
    		  //   since `null` is an instance
    		  ((string)null).print(4);
    		}
    	}
    }

created 3 years ago

C Sharp Online Compiler

Write, Run & Share C# code online using OneCompiler's C# online compiler for free. It's one of the robust, feature-rich online compilers for C# language, running on the latest version 8.0. Getting started with the OneCompiler's C# compiler is simple and pretty fast. The editor shows sample boilerplate code when you choose language as C# and start coding.

Read inputs from stdin

OneCompiler's C# online compiler supports stdin and users can give inputs to programs using the STDIN textbox under the I/O tab. Following is a sample program which takes name as input and print your name with hello.

using System;
 
namespace Sample
{
  class Test
    {
      public static void Main(string[] args)
       {
         string name;
         name = Console.ReadLine();
         Console.WriteLine("Hello {0} ", name);
	}
     }
}

About C Sharp

C# is a general purpose object-oriented programming language by Microsoft. Though initially it was developed as part of .net but later it was approved by ECMA and ISO standards.

You can use C# to create variety of applications, like web, windows, mobile, console applications and much more using Visual studio.

Syntax help

Data types

Data Type	Description	Range	size
int	To store integers	-2,147,483,648 to 2,147,483,647	4 bytes
double	to store large floating point numbers with decimals	can store 15 decimal digits	8 bytes
float	to store floating point numbers with decimals	can store upto 7 decimal digits	4 bytes
char	to store single characters	-	2 bytes
string	to stores text	-	2 bytes per character
bool	to stores either true or false	-	1 bit

Variables

Syntax

datatype variable-name = value;

Loops

1. If-Else:

When ever you want to perform a set of operations based on a condition or set of few conditions IF-ELSE is used.

if(conditional-expression) {
   // code
} 
else {
   // code
}

You can also use if-else for nested Ifs and If-Else-If ladder when multiple conditions are to be performed on a single variable.

2. Switch:

Switch is an alternative to If-Else-If ladder.

switch(conditional-expression) {    
case value1:    
 // code    
 break;  // optional  
case value2:    
 // code    
 break;  // optional  
...    
    
default:     
 // code to be executed when all the above cases are not matched;    
}

3. For:

For loop is used to iterate a set of statements based on a condition.

for(Initialization; Condition; Increment/decrement) {
  // code  
}

4. While:

While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.

while(condition) {
 // code 
}

5. Do-While:

Do-while is also used to iterate a set of statements based on a condition. It is mostly used when you need to execute the statements atleast once.

do {
  // code 
} while (condition);

Arrays

Array is a collection of similar data which is stored in continuous memory addresses. Array values can be fetched using index. Index starts from 0 to size-1.

Syntax

data-type[] array-name;

Methods

Method is a set of statements which gets executed only when they are called. Call the method name in the main function to execute the method.

Syntax

static void method-name() 
{
  // code to be executed
}