Csharp

What are Access Modifiers in C#?

Read: Here

program for factorial using recursion, while and for loop in c#

Calculate factorial using recursive function

public double factorial_Recursion(int number)

{

    if (number == 1)

        return 1;

    else

        return number * factorial_recursion(number - 1);

}

Calculate factorial using while loop

public double factorial_WhileLoop(int number)

{

    double result = 1;

    while (number != 1)

    {

        result = result * number;

        number = number - 1;

    }

    return result;

}

Calculate factorial using for loop

public double factorial_ForLoop(int number)

{

    double result = 1;

    for (int i = number; i > 1; i--)

    {

        result = result * i;

    }

    return result;

}

removing duplicate entries, records from Array 

Remove duplicate values through List Contain method

public string[] RemoveDuplicates(string[] inputArray)

{

    List<string> distinctArray = new List<string>();

    foreach (string element in inputArray)

    {

        if (!distinctArray.Contains(element))

            distinctArray.Add(element);

    }

    return distinctArray.ToArray<string>();

}

Delete Duplicate elements through ArrayList Contain method

public string[] RemoveDuplicates(string[] inputArray)

{

    System.Collections.ArrayList distinctArray = new System.Collections.ArrayList();

    foreach (string element in inputArray)

    {

        if (!distinctArray.Contains(element))

            distinctArray.Add(element);

    }

    return (string[])distinctArray.ToArray(typeof(string));

}

Remove Duplicate number / record of array through Linq Distinct method

public string[] RemoveDuplicates(string[] inputArray)

{

    return inputArray.Distinct().ToArray<string>();

}

public int[] RemoveDuplicates(int[] inputArray)

{

    return inputArray.Distinct().ToArray<int>();

}

Calling of RemoveDuplicates method -

string[] inputArray = { "array", "array", "distinct", "elememnt", "remove", "distinct", "delete","delete", "delete" };

string[] distinctArray = RemoveDuplicates(inputArray);