Mayor Bill de Blasio signed a handful of bills Tuesday that will change the city's food industry.

One new law requires mobile food vendors to display health inspection grades. City restaurants are already required to do so.

The grades of "A," "B" and "C" are given based on the number of violations.

There are also new laws aimed at improving work conditions for fast-food employees. One calls for certain employers to give workers 14 days' notice for schedule changes and pay them more if they are not given notice.

Another law bans so-called "clopenings," which is when fast-food employees work back-to-back shifts -- one closing the restaurant and the other opening the next day.

A third law requires requires employers to offer shifts to current employees before hiring more people, and a fourth allows fast-food employees to make donations to nonprofits through payroll deductions.

De Blasio also signed a bill Tuesday prohibiting on-call scheduling for retail employees.