C#: Find a number not in second array.

 Given two arrays, find the number from first array which not present in second array.


 class Program
    {
//method for dislpaying the array
        public void displayMatrix(List<int> arry)
        {
            for (int i = 0; i < arry.Count; i++)
            {
                Console.Write(arry[i] + " ");
            }
            Console.WriteLine();
            Console.WriteLine();
        }
//method for searching a number from first array which is not present in second array
        public void ValueSearch(List<int> first, List<int> second)
        {
            List<int> distinct = new List<int>();

            for (int i = 0; i < first.Count; i++)
            {
                for (int j = 0; j < second.Count; j++)
                {
//check each value in first array is equal to any of the value in second array
                    if (first[i] == second[j])
                    {
//if any value is equal, then change that value to zero or null in first array
                        first[i] = 0;
                        break;
                    }
                }
            }
//finding the values in first array
            for (int i = 0; i < first.Count; i++)
            {
//check for values not equal to zero or null
                if (first[i] != 0)
                {
// if not equal move that value to new array.
//so that new array contain only those values which are not in second array
                    distinct.Add(first[i]);
                }
            }
            Console.Write("The numbers not in second array: ");
//display new array with values that are only in first array
            displayMatrix(distinct);
        }
        static void Main(string[] args)
        {
//Initialise two list for represting values in first array and second array
           List<int> firstArr = new List<int>();
           List<int> secndArr = new List<int>();
//add values to first array
           firstArr.Add(2);
           firstArr.Add(3);
           firstArr.Add(4);
           firstArr.Add(6);
           firstArr.Add(1);
//add values to second array
           secndArr.Add(8);
           secndArr.Add(2);
           secndArr.Add(5);
           secndArr.Add(4);
           secndArr.Add(7);

            Program pgm = new Program();
            Console.Write("The First Array: ");
//display first array
            pgm.displayMatrix(firstArr);
            Console.Write("The Second Array: ");
//display second array
            pgm.displayMatrix(secndArr);
//call the method for value search
            pgm.ValueSearch(firstArr, secndArr);
        }
    }

Output:
 
The First Array: 2  3  4  6  1
The Second Array: 8  2  5  4  7
 The numbers not in second array: 3  6  1