using System;
using System.Collections.Generic;
using System.Linq;

namespace Demo
{
    public class Student
    {
        public int StudentID { get; set; }
        public string Name { get; set; }
        public int TotalMarks { get; set; }
    }

    class Program
    {
        public static void Main()
        {
            List<Student> listStudents = new List<Student>
            {
                new Student { StudentID= 101, Name = "Tom", TotalMarks = 800 },
                new Student { StudentID= 102, Name = "Mary", TotalMarks = 900 },
                new Student { StudentID= 103, Name = "Pam", TotalMarks = 800 }
            };

            // LINQ Query is only defined here and is not executed at this point
            // If the query is executed at this point, the result should not display Tim
            IEnumerable<Student> result = from student in listStudents
                                          where student.TotalMarks == 800
                                          select student;

            // Add a new student object with TotalMarks = 800 to the source
            listStudents.Add(new Student { StudentID = 104, Name = "Tim", TotalMarks = 800 });

            // The above query is actually executed when we iterate thru the sequence
            // using the foreach loop. This is proved as Tim is also included in the result
          
             //   Console.WriteLine(s.StudentID + "\t" + s.Name + "\t" + s.TotalMarks);
                
                Console.WriteLine(s[0]);
                
            
        }
    }
}

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
}