C#: Check if one string is rotation of another string

public void StringRotate()
{
   string str = "myblogpost";  //Declare a string
   string checkstr = "tsopgolbym"; //String to be checked
   char[] charArr = new char[str.Length]; //Intialize a new char array
    int j = 0;

    if (str.Length == checkstr.Length)// if both strings are equal length
   {
    for (int i = str.Length-1; i >=0; i--) //then continue to check rotation
    {
        charArr[j] = str[i];
        j++;
    }
    string str1 = new string(charArr); // Intialize a new string
    if (str1 == checkstr)
    {
        Console.WriteLine("Both strings are rotation strings");
    }
    else
    {
        Console.WriteLine("Both strings are not a rotation strings");
    }
    }
    else // if both strings are not equal length
    {
     Console.WriteLine("Both strings are not equal length and not rotation strings");
     }
 }

Output: Both strings are rotation strings

C#: Check whether an element is present in an array and find its index?

public void ElementSearch()
{
  int[] eleArray = new int[5]{4,1,8,5,9}; // Assign values to array
  int valSearch = 5; //Search for a value
  int counter = 0; // Set a counter, if the value doesn''t exist in an array
     
  for(int i=0; i<=4; i++) //Iterate to all elements in an array
  {
    if (eleArray[i] == valSearch)// Check each value is equal to value to search
    {
       Console.WriteLine("Value found and is in index " + i + " of an array");
    }
    else //if value not found, increment the counter
    {
       counter++;
       if (counter == eleArray.Length) //counter reach arraylength, value notfound.
      {
        Console.WriteLine("Sorry! Value not found");
      }
    }
  }
}

Output: Value found and is in index 3 of an array

C#: Using HashTable

public void HashTable()
        {
            Hashtable hash = new Hashtable();
            hash.Add("Name1", "Alex");
            hash.Add("Name2", "Peter");
      
           //Gives the value of key Name2
             Console.WriteLine(hash["Name2"].ToString());

           //Check Name1 is on list
            Console.WriteLine(hash.Contains("Name1").ToString());

            //Remove Name2 key/value and check if it still contains.
            hash.Remove("Name2");
            Console.WriteLine(hash.Contains("Name2").ToString());

            try
            {
               //To display an item already removed from list and catched by exception.
                Console.WriteLine(hash["Name2"].ToString());
            }
            catch (NullReferenceException)
            {
                Console.WriteLine("The key value missing");
            }

           //Add two more value to list
            hash.Add("Name2", "Sam");
            hash.Add("Name3", "Kite");
          
           //To iterates the items in hashtable.
            IDictionaryEnumerator enumr=hash.GetEnumerator();
            while (enumr.MoveNext())
            {
                Console.WriteLine(enumr.Key.ToString());
            }
        }

Output:Peter
            True
            False
            The key value missing
            Name1
            Name2
            Name3

C#: Replace a String

public void ReplaceString()
{
   string str = "Hello how are you!";
   string result= str.Replace(" ","--");
   Console.WriteLine(result);
}

Output: Hello--how--are--you!

C#: Display Random String

public void RandomString()
{
 string[] randStr = new string[5]{"hi","hello","how","are","you"};
 int indexStr = rnd.Next(randStr.Length);
 Console.WriteLine(randStr[indexStr]);
}

Output: hello

C#: Display Random Numbers

public void RandomNumber()
 {
 Random rnd = new Random();
int[] randArray = new int[10];
 int rand1 ;
for (int i = 0; i < 10; i++)
{
 rand1 = rnd.Next(1, 10); // Random numbers between 1 and 10
 Console.WriteLine(rand1);
 }
}

Output: 8
              2
              6
              4
              5
              7
              6
              3
              3
              2
              

C#: Check whether a string is substring of another string?

public void CheckForSubstring()
        {
            string str = "onetwothree";
            bool result = str.Contains("two");
            Console.WriteLine(result);  //returns True

            result = str.Contains("Two"); //returns False, bcoz C# is case sensitive
            Console.WriteLine(result);
        }

Output: True
              False  

C#: String Reversal

 public void StringReverse()
        {
           string str = "stringtoberevered";

            char[] chararr = new char[str.Length];

            chararr = str.ToCharArray();
            Console.Write("The Reversed String = ");
            for (int i = str.Length - 1; i >= 0; i--)
            {

                Console.Write(chararr[i]);

            }
            Console.WriteLine();
        }

Output: dereverebotgnirts

C#: How to find minimum value from an array of integers?

  public void MinimumValInt()
        {
            int[] intArray = new int[7] { 10,4,5,1,7,15,12};
            int minVal = intArray[0];

            for (int i = 1; i < intArray.Length; i++)
            {
                if (intArray[i] < minVal)
                {
                    minVal = intArray[i];
                }
            }
            Console.WriteLine("Minimum value= "+minVal);
        }


Output: Minimum value=1