public static String lowerFirst(String s){
  if (s.isEmpty()) {
    return s;
  }
  char c=s.charAt(0);
  if (Character.isLowerCase(c)) {
    return s;
  }
  c=Character.toLowerCase(c);
  return c + s.substring(1);
}

public static String lowerFirst ( String s ) { if ( s . isEmpty ( ) ) { return s ; } char c = s . charAt ( 0 ) ; if ( Character . isLowerCase ( c ) ) { return s ; } c = Character . toLowerCase ( c ) ; return c + s . substring ( 1 ) ; }
returns a string with the first char lowered if it is in upper case , other return the original one .
