Program to Display Prime Numbers Between Intervals Using Function - (C# Basic Programs)

Finding prime numbers is a common programming exercise that helps improve problem-solving skills. In this tutorial, we will discuss a program to display prime numbers between two intervals using a function in the C# programming language.

Syntax

The syntax for finding prime numbers in C# can be defined using the following code structure:

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

using System;

class Program
{
    static void Main(string[] args)
    {
        int start, end;

        Console.Write("Enter the start of range: ");
        start = int.Parse(Console.ReadLine());

        Console.Write("Enter the end of range: ");
        end = int.Parse(Console.ReadLine());

        Console.WriteLine("Prime numbers between {0} and {1} are: ", start, end);

        for (int i = start; i <= end; i++)
        {
            if (IsPrime(i))
            {
                Console.Write(i + " ");
            }
        }

        Console.ReadLine();
    }

    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;
    }
}

Output:

Enter the start of range: 1
Enter the end of range: 20
Prime numbers between 1 and 20 are: 
2 3 5 7 11 13 17 19

Explanation

The program creates a function called IsPrime() that takes a number and returns a boolean indicating whether the number is prime or not. The function is then used in a loop to check each number in the user-specified range. If a number is prime, it is added to the output.

Use

This program is used to display prime numbers between two intervals using a function in the C# programming language. It is used to improve problem-solving skills and develop a better understanding of functions, loops, and conditionals.

Summary

In this tutorial, we discussed a program to display prime numbers between two intervals using a function in the C# programming language. We covered the syntax, example, output, explanation, and use of finding prime numbers in C#. By practicing these exercises, programmers can improve their problem-solving skills and become better equipped to tackle complex coding challenges related to prime numbers.