question: public static double guessDate ( String s ) { int i = s . length ( ) ; char c ; do { i -- ; c = s . charAt ( i ) ; } while ( i >= 0 && ( Character . isDigit ( c ) || c == '.' ) ) ; if ( i == s . length ( ) ) { return 0.0 ; } return Double . parseDouble ( s . substring ( i + 1 ) ) ; }
target:  Returns -1 if there is no number suffix