Exercise solution: UML diagram

- [Instructor] Here we want to draw UML … that describes the relationships between these objects. … Here's how I would go about it. … We'll start with a house and a room. … Room is special, it's going to have some children. … So, let's connect with the open triangle arrow … kitchen, bathroom, and bedroom, … signifying that those three objects are rooms. … Kitchen is a room, bathroom is a room, … bedroom is a room. … How are these related to the house? … Well, I know I'm going to use … one of my diamond-headed arrows … and I have a choice between a shaded one … or an open one. … Because it doesn't really make sense … for a kitchen to exist outside of a house, … I'm going to choose the shaded diamond. … That signifies a deeper connection. … Same for bathroom, same for bedroom. … I also know a little more about these, … so I can put a cardinality. … For the kitchen there's only going to be one kitchen, … unless you're a zillionaire. … We could have multiple bathrooms though, … so let's put an asterisk there. …