Reverse Each Word in a Sentence without using any Function/String Variables in C#

Let say, input character array is “This is a good day”. I need the output as “sihT si a doog yad”.

Logic:

To do this, first we have to fetch the each word from the sentence based on the space and then swap the character in the word.

Code:

string sentense = "This is a good day";
char[] arr = sentense.ToCharArray();
int temp = 0;

//Logic to iterate up to end of the line.
for (int fl = 0; fl <= arr.Length - 1;fl++ )
{
    int count = temp;
    int num1 = 1;
    //To get the word before space or the last word
    if (arr[fl] == ' ' || fl == arr.Length - 1)
    {
        if (fl == arr.Length - 1)
        {
            for (int c = fl; c >= temp; c--)
            {
                //Swap the word
                if (num1 <= (fl - temp) / 2)
                {
                    char tempC = arr[count];
                    arr[count] = arr[c];
                    arr[c] = tempC;
                    count++;
                    num1++;
                }
            }
        }
        else
        {
            for (int c = fl - 1; c >= temp; c--)
            {

                if (num1 <= (fl - temp) / 2)
                {
                    char tempC = arr[count];
                    arr[count] = arr[c];
                    arr[c] = tempC;
                    count++;
                    num1++;
                }
            }
        }
        temp = fl + 1;
    }

}

string newLine = new string(arr);

Output:



I have attached the class file also for reference.