Day 81
Day 81 관련
Project 24, part two
If there’s one thing you need to know about language, it’s this: language is complicated. And that’s the number one reason why Swift’s strings are also complicated: they are designed to do the right thing by default, so you get support for all known languages, plus fantasy languages like Klingon and Elvish, and even emoji – all without having to do anything special.
Although this might seem like a pointless technicality, you’d do well to remember this quote from Frank Chimero: “people ignore design that ignores people.” Our job isn’t just to write great code and hope for the best, but instead to put our users needs front and centre all the time – to make sure we meet their needs and solve their problems.
If your software falls on the first hurdle – if it’s unable to handle their language – then you might as well not bother.
Today you should work through the wrap up chapter for project 24, complete its review, then work through all three of its challenges.
Wrap up
Wrap up
Coming into this project you might thought strings were trivial, but I hope I’ve shown you that there’s more to them than meets the eye.
We’ve looked at how strings are different from arrays, how we can write useful extensions for strings, how Swift lets us combine functions together beautifully, and how NSAttributedString lets us add formatting to strings.
Of course, we’ve only just scratched the surface of strings here, but the challenges below will encourage you to write some extensions of your own so you get a better feel for how it works.
Review what you learned
Anyone can sit through a tutorial, but it takes actual work to remember what was taught. It’s my job to make sure you take as much from these tutorials as possible, so I’ve prepared a short review to help you check your learning.
Click here to review what you learned in project 24.
Challenge
One of the best ways to learn is to write your own code as often as possible, so here are three ways you should try your new knowledge to make sure you fully understand what’s going on:
- Create a
Stringextension that adds awithPrefix()method. If the string already contains the prefix it should return itself; if it doesn’t contain the prefix, it should return itself with the prefix added. For example:"pet".withPrefix("car")should return “carpet”. - Create a
Stringextension that adds anisNumericproperty that returns true if the string holds any sort of number. Tip: creating aDoublefrom aStringis a failable initializer. - Create a
Stringextension that adds alinesproperty that returns an array of all the lines in a string. So, “this\nis\na\ntest” should return an array with four elements.
Wrap up - Additional
That’s another project finished, and one that has given you a glimpse inside Swift’s inner working – make sure you share the extensions you write with others!
