question: public String toString ( int digits , boolean trailing ) { if ( isEmpty ( ) ) return "null vector" ; StringBuffer text = new StringBuffer ( ) ; FlexibleDecimalFormat nf = new FlexibleDecimalFormat ( digits , trailing ) ; nf . grouping ( true ) ; for ( int i = 0 ; i < size ( ) ; i ++ ) nf . update ( get ( i ) ) ; int count = 0 ; int width = 80 ; String number ; for ( int i = 0 ; i < size ( ) ; i ++ ) { number = nf . format ( get ( i ) ) ; count += 1 + number . length ( ) ; if ( count > width - 1 ) { text . append ( '\n' ) ; count = 1 + number . length ( ) ; } text . append ( " " + number ) ; } return text . toString ( ) ; }
target:  Convert the IntVecor to a string