My Editor is Confused

But before we go on, we need to help my editor. It's confused. Inside printShipSummary(), my editor doesn't seem to recognize the sayHello() method on Ship, it thinks it doesn't exist. But down at the bottom of the file, when I call doesGivenShipHaveMoreStrength(), it's not highlighted in yellow - that means my editor does see that this method exists. So what gives? Why doesn't it recognize the sayHello() function?

If you just look at the printShipSummary() function, all that my editor knows is that we're passing in some argument called $someShip, but it doesn't know what it is. Is it a string? A boolean? A Ship object? We know that this will be a Ship object, because we're creating Ship objects below and passing those as the argument. But our editor has no idea. And for that reason, it doesn't know to look on the Ship class to see that there's a sayHello() function.

You don't need to fix this, it's totally fine. But if you want to, you can use PHP documentation to give your editor a little hint about what the heck this $someShip variable is. By using this syntax, you can say this this is a Ship object:

And as soon as I do that, those ugly yellow highlights go away, and I even get auto-completion on new code I write.

As nice as this is, it makes no functional difference - your code isn't behaving any different than before. This is just a "nice" thing you can do to help you and your editor get along.