using System;
using System.ComponentModel.Design;
using System.Diagnostics.CodeAnalysis;
using System.Net.Mail;
using System.Numerics;
using System.Reflection.Metadata.Ecma335;

namespace test10b
{
  class Program
  {
    static void Main(string[] args)
    {
      int menu;
      Console.Write("Введите значение №1: ");
      int a = Convert.ToInt32(Console.ReadLine());
      Console.Write("Введите значение №2: ");
      int b = Convert.ToInt32(Console.ReadLine());
      do
      {
        Console.WriteLine("------------------");
        Console.WriteLine("1 - Сумма");
        Console.WriteLine("2 - Разность");
        Console.WriteLine("3 - Умножение");
        Console.WriteLine("4 - Деление");
        Console.WriteLine("0 - Выход");
        Console.WriteLine("------------------");
        menu = Convert.ToInt32(Console.ReadLine());
        switch (menu)
        {
          case 1:
            sum(a,b);
            break;
          case 2:
            sub(a,b);
            break;
          case 3:
            mul(a,b);
            break;
          case 4:
            div(a,b);
            break;
        }
      }
      while (menu != 0);
      Console.ReadKey();
    }
    static void sum(int k, int w)
    {
      Console.WriteLine("Сумма: {0}", k+w);
      Console.ReadKey();
    }
    static void sub(int k, int w)
    {
      Console.WriteLine("Разность: {0}", k-w);
      Console.ReadKey();
    }
    static void mul(int k, int w)
    {
      Console.WriteLine("Умножение: {0}", k*w);
      Console.ReadKey();
    }
    static void div(int k, int w)
    {
      Console.WriteLine("Деление: {0}", k/w);
      Console.ReadKey();
    }
  }
}
by

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 TypeDescriptionRangesize
intTo store integers-2,147,483,648 to 2,147,483,6474 bytes
doubleto store large floating point numbers with decimalscan store 15 decimal digits8 bytes
floatto store floating point numbers with decimalscan store upto 7 decimal digits4 bytes
charto store single characters-2 bytes
stringto stores text-2 bytes per character
boolto 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
}