//string concatenation with for looppublic string ReverseA(string text){  char[] cArray = text.ToCharArray();  string reverse = String.Empty;  for (int i = cArray.Length - 1; i > -1; i--)  {    reverse += cArray[i];  }  return reverse;}// Array.Reverse functionpublic string ReverseB(string text){  char[] charArray = text.ToCharArray();  Array.Reverse(charArray);  return new string(charArray);}// push/pop Stack<>public string ReverseC(string text){  Stack resultStack = new Stack();  foreach (char c in text)  {    resultStack.Push(c);  }  StringBuilder sb = new StringBuilder();  while (resultStack.Count > 0)  {    sb.Append(resultStack.Pop());  }  return sb.ToString();}// LINQpublic string ReverseD(string text){  return new string(text.ToCharArray().Reverse().ToArray());}// StringBuilderpublic string ReverseE(string text){  char[] cArray = text.ToCharArray();  StringBuilder reverse = new StringBuilder();  for (int i = cArray.Length - 1; i > -1; i--)  {    reverse.Append(cArray[i]);  }  return reverse.ToString();}