1. Functions as everyday items

2. def donation_box(coin):
Do you get anything back (directly)?
No. So this is a void function.

3. def recycling_bin(paper, plastic, other):
Do you get anything back (directly)?
No. So this is a void function.

4. def gumball_machine(coin):
Do you get anything back (directly)?
Yes, candy! So this is a value-returning function.

5. def traffic_light():
Clearly you don’t pass anything to the traffic light, so no arguments and hence no parameters,
but do you get something from “using” the traffic light?
Yes, a traffic signal. So this is a value-returning function.