C# Project Problem

Create a 2-dimensional (3 x 3) integer array which contains 9 random numbers ranged from 0 to 100. For each number, determine whether the number is a prime number or not. You should define a method to test whether a number is prime or not. A prime number (n) meets the following requirements:

n must be larger than 1.
If n is greater than 1, then start dividing by 2, 3, …, n-1 and check the remainder. If none of remainder equals to 0, then n is a prime number. Otherwise, it is not.

Your programme should:

Print all elements in 3 rows
Print the total number of prime numbers.
Print all location(s) of prime number(s) and their values (if there is any).

Sample Screen Output:

Row 1: 5 / 81 / 45

Row 2: 21 / 27 / 17

Row 3: 31 / 77 / 41

Total Number of Prime Number: 4

Row 1 and Column 1: 5

Row 2 and Column 3: 17

Row 3 and Column 1: 31

Row 3 and Column 3: 41

Hi Lorraine,

I created a class PrimeNumChecker and main program is creating object of PrimeNumChecker class and calling its method to give desired output.

Here is the solution:

class PrimeNumChecker
    {
        int [,] matrix = new int [3,3];
        Random rndm = new Random(0);

        public void CreateMatrix ()
        {
            for (int i=0; i< 3; i++)
                for (int j=0; j<3; j++)
            {

                matrix[i,j] = Convert.ToInt32(rndm.Next(100));
            }
        }

        public void DisplayMatrix ()
        {
            Console.WriteLine ("Input Matrix is:\n");
            for (int i=0; i< 3; i++)
            {
                Console.Write("ROW-"+(i+1)+ "\t");
                for (int j=0; j<3; j++)
                {
                    Console.Write (matrix [i, j] + "\t");
                }
                Console.WriteLine ();
            }
        }

        public void ProcessMatrix ()
        {
            CountPrimeNumbers();
            DisplayPrimeNumber();
        }

        private void CountPrimeNumbers ()
        {
            int primeNumCount =0;

            for (int i=0; i< 3; i++)
            {
                for (int j=0; j<3; j++)
                {
                    if(IsPrimeNumber(matrix [i, j]))
                    {
                        primeNumCount ++;
                    }
                }
            }
            Console.WriteLine ("\nTotal number of prime numbers are: "+ primeNumCount);
        }

        private void DisplayPrimeNumber ()
        {
             for (int i=0; i< 3; i++)
            {
                for (int j=0; j<3; j++)
                {
                    if(IsPrimeNumber(matrix [i, j]))
                    {
                        Console.WriteLine ("Row "+ (i+1) + " Column "+ (j+1) + ": " +matrix[i,j]);
                    }
                }
            }
        }

        private bool IsPrimeNumber(int num)
        {

            bool bPrime = true;

            int factor = num / 2;
            int i = 0;

            for (i = 2; i <= factor; i++)
            {
                if ((num % i) == 0)

                    bPrime = false;
            }

            return bPrime;
        }
    }

    class MainClass
    {
        public static void Main (string[] args)
        {
            PrimeNumChecker objPrimeChecker = new PrimeNumChecker();
            objPrimeChecker.CreateMatrix();
            objPrimeChecker.DisplayMatrix();
            objPrimeChecker.ProcessMatrix();

            Console.Read();
        }
    }

Output comes like:

2 Replies

Know the answer? Post it — somebody with the same question will find it here.

Hemant Srivastava14y ago
Accepted answer
Hi Lorraine,

I created a class PrimeNumChecker and main program is creating object of PrimeNumChecker class and calling its method to give desired output.

Here is the solution:

class PrimeNumChecker
    {
        int [,] matrix = new int [3,3];
        Random rndm = new Random(0);

        public void CreateMatrix ()
        {
            for (int i=0; i< 3; i++)
                for (int j=0; j<3; j++)
            {

                matrix[i,j] = Convert.ToInt32(rndm.Next(100));
            }
        }

        public void DisplayMatrix ()
        {
            Console.WriteLine ("Input Matrix is:\n");
            for (int i=0; i< 3; i++)
            {
                Console.Write("ROW-"+(i+1)+ "\t");
                for (int j=0; j<3; j++)
                {
                    Console.Write (matrix [i, j] + "\t");
                }
                Console.WriteLine ();
            }
        }

        public void ProcessMatrix ()
        {
            CountPrimeNumbers();
            DisplayPrimeNumber();
        }

        private void CountPrimeNumbers ()
        {
            int primeNumCount =0;

            for (int i=0; i< 3; i++)
            {
                for (int j=0; j<3; j++)
                {
                    if(IsPrimeNumber(matrix [i, j]))
                    {
                        primeNumCount ++;
                    }
                }
            }
            Console.WriteLine ("\nTotal number of prime numbers are: "+ primeNumCount);
        }

        private void DisplayPrimeNumber ()
        {
             for (int i=0; i< 3; i++)
            {
                for (int j=0; j<3; j++)
                {
                    if(IsPrimeNumber(matrix [i, j]))
                    {
                        Console.WriteLine ("Row "+ (i+1) + " Column "+ (j+1) + ": " +matrix[i,j]);
                    }
                }
            }
        }

        private bool IsPrimeNumber(int num)
        {

            bool bPrime = true;

            int factor = num / 2;
            int i = 0;

            for (i = 2; i <= factor; i++)
            {
                if ((num % i) == 0)

                    bPrime = false;
            }

            return bPrime;
        }
    }

    class MainClass
    {
        public static void Main (string[] args)
        {
            PrimeNumChecker objPrimeChecker = new PrimeNumChecker();
            objPrimeChecker.CreateMatrix();
            objPrimeChecker.DisplayMatrix();
            objPrimeChecker.ProcessMatrix();

            Console.Read();
        }
    }

Output comes like:
Hemant Srivastava14y ago
If this helps you, please mark the above answer as an accepted answer. If not, let me know your issue.

Thanks,
Hemant