11. Writing Classes 4

You are going to work with a list of stored items and their amounts, like this:

Food 500
Water 300
Food 200
Fish 7
Water 800

Supply Class

The first step is to write a Supply class that will hold one line of information.

Supply food1 = new Supply("Food", 500);
System.out.println(food1); // "500 Food"

Include a method to make the Supply object print out as shown above.

Add in two more methods:

public boolean sameKind(Supply other) { ... }
public combineWith(Supply other) { ... }

The sameKind method returns true when the two supplies have the same kind. The combineWith method has the precondition that the this.sameKind(other) is true. It changes the object by adding the amount of the other object to it.

StoreRoom class

The StoreRoom represents the information in a list of supplies, as shown at the start. It has a void combineAll() method that combines all matching supplies into one.

// You set up contents = an ArrayList of Supplies.
System.out.println(contents);
// [500 Food, 300 Water, 200 Food, 7 Fish, 800 Water]
StoreRoom room030 = new StoreRoom(contents);
room030.combineAll();
System.out.println(room030);
// [700 Food, 1100 Water, 7 Fish]

Write the StoreRoom class.