prime numbers c# code example

Example 1: isprime c#

public static bool IsPrime(int number)
{
    if (number <= 1) return false;
    if (number == 2) return true;
    if (number % 2 == 0) return false;

    var boundary = (int)Math.Floor(Math.Sqrt(number));

    for (int i = 3; i <= boundary; i+=2)
        if (number % i == 0)
            return false;

    return true;        
}

Example 2: how to check prime number in c#

using System;  
  public class PrimeNumberExample  
   {  
     public static void Main(string[] args)  
      {  
          int n, i, m=0, flag=0;    
          Console.Write("Enter the Number to check Prime: ");    
          n = int.Parse(Console.ReadLine());  
          m=n/2;    
          for(i = 2; i <= m; i++)    
          {    
           if(n % i == 0)    
            {    
             Console.Write("Number is not Prime.");    
             flag=1;    
             break;    
            }    
          }    
          if (flag==0)    
           Console.Write("Number is Prime.");       
     }  
   }