question: public final static int parseInt ( String str ) { char c = str . charAt ( 0 ) ; int length = str . length ( ) ; boolean negative = ( c == '-' ) ; int offset = 1 ; if ( negative ) { if ( length == 1 || length > 10 ) { return Integer . parseInt ( str ) ; } c = str . charAt ( offset ++ ) ; } else { if ( length > 9 ) { return Integer . parseInt ( str ) ; } } if ( c > '9' || c < '0' ) { return Integer . parseInt ( str ) ; } int num = c - '0' ; if ( offset < length ) { c = str . charAt ( offset ++ ) ; if ( c > '9' || c < '0' ) { return Integer . parseInt ( str ) ; } num = ( num * 10 ) + ( c - '0' ) ; if ( offset < length ) { c = str . charAt ( offset ++ ) ; if ( c > '9' || c < '0' ) { return Integer . parseInt ( str ) ; } num = ( num * 10 ) + ( c - '0' ) ; if ( offset < length ) { do { c = str . charAt ( offset ++ ) ; if ( c > '9' || c < '0' ) { return Integer . parseInt ( str ) ; } num = ( num * 10 ) + ( c - '0' ) ; } while ( offset < length ) ; } } } return negative ? - num : num ; }
target:  Helper method to (more) efficiently parse integer numbers from String values.