Should any section or provision of this chapter be declared by the courts to be unconstitutional or invalid for any reason, such decision shall not affect the validity of the chapter as a whole nor the validity of any other section or provision of the chapter than the one so declared.

All existing ordinances or parts of ordinances, which are contrary to the provisions of this chapter, are hereby repealed to the extent necessary to give this chapter full force and effect.

This chapter shall take effect 20 days after its passage when published as required by law.