question: public int format ( int val , byte [ ] buf , int off , int len ) { if ( val == Integer . MIN_VALUE ) { if ( len > ByteFormatter . NUMBER_BASE ) { return format ( "-2147483648" , buf , off , len ) ; } else { truncationFiller ( buf , off , len ) ; return off + len ; } } int pos = Math . abs ( val ) ; int ndig = 1 ; int dmax = ByteFormatter . NUMBER_BASE ; while ( ndig < ByteFormatter . NUMBER_BASE && pos >= dmax ) { ndig ++ ; dmax *= ByteFormatter . NUMBER_BASE ; } if ( val < 0 ) { ndig ++ ; } if ( ndig > len || ndig > buf . length - off ) { truncationFiller ( buf , off , len ) ; return off + len ; } off += ndig ; int xoff = off - 1 ; do { buf [ xoff ] = ByteFormatter . DIGITS [ pos % ByteFormatter . NUMBER_BASE ] ; xoff -- ; pos /= ByteFormatter . NUMBER_BASE ; } while ( pos > 0 ) ; if ( val < 0 ) { buf [ xoff ] = ( byte ) '-' ; } return off ; }
target:  Format an int into an existing array.