question: public static int [ ] copyOfRange ( int [ ] original , int start , int end ) { if ( start <= end ) { if ( original . length >= start && 0 <= start ) { int length = end - start ; int copyLength = Math . min ( length , original . length - start ) ; int [ ] copy = new int [ length ] ; System . arraycopy ( original , start , copy , 0 , copyLength ) ; return copy ; } throw new ArrayIndexOutOfBoundsException ( ) ; } throw new IllegalArgumentException ( ) ; }
target:  Copies elements in original array to a new array, from index start(inclusive) to end(exclusive). The first element (if any) in the new array is original[from], and other elements in the new array are in the original order. The padding value whose index is bigger than or equal to original.length - start is 0.