Objects Interact

Hey Brittany J.
It's pretty simple. $this is some sort of magic variable, for example, if you call $myShip->doesGivenShipHaveMoreStrength() than inside doesGivenShipHaveMoreStrength(), $this will be $myShip object, but if you call $otherShip->doesGivenShipHaveMoreStrength() than it will be $otherShip.
So $this variable inside Class is always refers to the object from which the method was called.

Cheers! Hope it's more clear now.

Hey Md mamunur R.!

GREAT question! Let me rewrite this function so that it does the SAME thing, but is a little bit more clear:

public function doesGivenShipHaveMoreStrength($givenShip){
    if ($givenShip->strength > $this->strength) {
        return true;
    } else {
        return false;
    }
}

If you look at this function, I hope it's more clear. If the $givenShip strength is greater than (>) THIS ship's strength, then the method returns true. Else, it returns false.

This code does the exact same thing as my original code:

return $givenShip->strength > $this->strength;

In this line, PHP first determines the value of $givenShip->strength > $this->strength, which will be true or false. Then, it returns that value (it returns true or false).

If this "shorter" way of writing the method looks confusing to you, then you should feel comfortable writing it the longer, more clear way. Code readability is really important - you certainly don't always need to do things the "shortest" way.

Cheers!