### Reverse a string in place character string reverse    Posted: 5 years ago Edit answers (1) views (2167)

Write a function to reverse a String in place without creating another String.

 Posted: 5 years ago 0 0 Edit Create a character array from the input String. Take two pointers at the first and last index of the array. Interchange their values. Move the pointers - the first one in forward direction and the second one in backward direction. Repeat the last two steps while the first pointer is less than the second pointer. Example - Let the input string be '$$algoqueue$$'. Time complexity = $$O(n)$$.public string reverseString(String input){ /* Input string is null */ if (input == null) return null; /* string to character array */ char[] string2CharArray = input.ToCharArray(); /* First pointer */ int firstIndex = 0; /* Second pointer */ int lastIndex = input.length - 1; while (firstIndex < lastIndex){ /* Exchange the values at the two pointer */ char temp = string2CharArray[firstIndex]; string2CharArray[firstIndex] = string2CharArray[lastIndex]; string2CharArray[lastIndex] = temp; /* Move the first pointer forward */ firstIndex ++; /* Move the second pointer backward */ lastIndex --; } return String.valueOf(string2CharArray); }