5. Acting differently (parameters)
In the dancing example in Module 4, every dancer does the same thing. Is that how you dance? Do you do exactly the same as everyone else? I doubt it! At a party, there'll be lots of dancers, but they'll all be doing it just a little (or a lot!) differently. For example, in Module 4, I'm sure the zombie would do a crazier dance than the teacher.
Notice how we're thinking about activities here. Every character is going to do a dance in the middle (we've learned how to do that already), but each of them might do a part of it slightly differently - for example, when they get to the jump and spin part, some may spin more times than others. I bet the zombie can do a crazy number of spins. See? All the characters will do the basic moves of the dance - this activity is shared by all of them - but there's a little variation in the number of spins each of them puts in. A common part with variation.
Alice let's us add in this variation, and we'll be exploring this now.
so let's have a look at it in action before going any further...
Things you will learn in this module:
- Up to now, our methods have only taken one parameter at most, but we will see how methods can take any number of parameters.
- The values we've passed into methods have so far always been characters in our world. We will see that we can pass in any kind of value - particularly numerical values - and how this can be useful in specifying the variation we are going to explore.
Vocabulary for this module:
Parameter Type: This is specified at the time the parameter is created, and indicates what kind of value to expect when the method is called - for example, will it be a character in the world or a numerical value?
Default Value: If a parameter is added to an existing method, then Alice automatically updates every call to the method to include a parameter value. Alice uses a default or standard value for this - for example, for the numeric type, Alice uses the number one.