question: public static void appendZeroPadded ( StringBuilder buff , int length , long positiveValue ) { if ( length == 2 ) { if ( positiveValue < 10 ) { buff . append ( '0' ) ; } buff . append ( positiveValue ) ; } else { String s = Long . toString ( positiveValue ) ; length -= s . length ( ) ; while ( length > 0 ) { buff . append ( '0' ) ; length -- ; } buff . append ( s ) ; } }
target:  Append a zero-padded number to a string builder.