public static char [] reverse(char [] str) { int j = str.length - 1; for(int i = 0; i < j; i++, j--) { str[i] ^= str[j]; str[j] ^= str[i]; str[i] ^= str[j]; } return str; } public static String reverse(String str) { return new StringBuffer(str).reverse().toString(); } public static char[] reverse2(char [] str) { int length = str.length; for (int i = 0; i < length / 2; i++) { char c = str[i]; str[i] = str[length-i-1]; str[length-i-1] = c; } return str; }