Refactoring: Simplify Arithmetic

- [Instructor] I've gone ahead and extracted methods…to identify the other special items,…and I've included a copy of my code…so you can begin at the same point as me.…Here's another kind of expression that I'm seeing…repeated in this code.…At line 24, we see a line that says…item.quality equals item.quality minus one.…At line 29, item.quality equals item.quality plus one.…These sorts of expressions can be simplified.…We can simplify the arithmetic of these expressions…to decrement the value of a variable at by one.…

We could simplify this to be item.quality minus minus.…Having done that, let's rerun the tests…to make sure we didn't break anything.…Alright, so the pin down tests are continuing…to keep us safe.…Let's try the same thing at line 29, we'll change this from…item.quality equals item.quality plus one…to the simpler item.quality plus plus, and rerun the tests.…

We'll scroll down and continue making this kind of change.…So we've got another one at line 34.…Every time we do this, we'll rerun the tests…to make sure we didn't accidentally type minus minus…