Write a C# sharp Program to check wheather the given string is Palindrome or not. (Ex: LEVEL is palindrome).Don't use inbuild string functions.

Answer:

PALINDROME string is sequence of letters that is the same forward as backward. Example is LEVEL.

class Program

{

        public bool IsPalindrome(string sInput)

        {            

            int iLengthofInput = 0;



            //Find Length of the string. 

            foreach(char chr in sInput)

                iLengthofInput++;



            char[] sArrReverse = new char[iLengthofInput];



            int iIncr =iLengthofInput-1;

            foreach(char chr in sInput)

            {

               sArrReverse[iIncr] = chr;

                iIncr--;

            }



            string sRevString = new string(sArrReverse);



            #region AnotherWay for string initializng

            //string sRevString = "";

            //for(int i = 0; i < iLengthofInput; i++)

            //{

            //    sRevString += sArrReverse[i];

            //}

            #endregion



            if (sRevString == sInput)

                return true;

            else

                return false;         



        }

	static void Main(string[] args)

        {

            Program pObj = new Program();

            Console.WriteLine(pObj.IsPalindrome("LEVEL");

	    Console.Read();

	}

}

In the above code I am finding the length of the string. For example : LEVEL - length is 5.

char[] sArrReverse = new char[iLengthofInput];



            int iIncr =iLengthofInput-1;

            foreach(char chr in sInput)

            {

               sArrReverse[iIncr] = chr;

                iIncr--;

            }

In the above code I am creating the arrary called "sArrReverse" and initializing with length of input string.
In Foreach loop I am assigning values of input string in reverse order. So now sArrReverse contains "LEVEL" which is reverse form of original input string "LEVEL".
I am creating a string "sRevString" and initializing with "sArrReverse" value in the following code

 string sRevString = new string(sArrReverse);

OR

string sRevString = "";

   for(int i = 0; i < iLengthofInput; i++)

   {

      sRevString += sArrReverse[i];

   }

Using If condition I am checking both strings and returning the value depends on condition.