(C #) Reverses the string, reversing the word in a sentence.

This is a very basic interview question, but to be considerate.

First, reverse a string:

The basic idea is to change to a char array, then call the method inside C #, or set two index, traverse from head to tail, and swap.

Method One: Array.reverse (char *). Note that the string will be null or empty at the beginning.

         Public Static string ReverseString (string  input)        {            if  (String.IsNullOrEmpty (input))            {                 return input;             }             Char [] Chararray = input. ToCharArray ();            Array.reverse (Chararray);             return New String (Chararray);         }

Method two: Swap characters.

         Public Static stringReverseString1 (stringinput) {            if(String.IsNullOrEmpty (input)) {returninput; }            Char[] Chararray =input.            ToCharArray (); Chartmp;  for(inti =0, j = chararray.length-1;  I < J; i++, j--) {tmp=Chararray[i]; Chararray[i]=Chararray[j]; CHARARRAY[J]=tmp; }            return New string(Chararray); }

Reverse the words in a sentence:

         Public Static stringReversewords (stringinput) {            if(String.IsNullOrEmpty (input)) {returninput; }            string[] splits = input. Split (' '). Select (str=>Str. Trim ()).            ToArray (); StringBuilder Output=NewStringBuilder ();  for(inti = splits. Length-1; I >=0; i--) {output.                 Append (Splits[i]); if(I! =0) {output. Append (" "); }            }            returnoutput.         ToString (); }

(C #) Reverses the string, reversing the word in a sentence.