Numbers to Arrays and Vice Versa

Write two functions:

1. to_list(), which converts a number to an integer list of its digits.
2. to_number(), which converts a list of integers back to its number.

Examples

to_list(235) ➞ [2, 3, 5]

to_list(0) ➞ [0]

to_number([2, 3, 5]) ➞ 235

to_number([0]) ➞ 0

Notes

All test cases will be weakly positive numbers: >= 0