100 Days Of Swift

December 29, 2020

I started Paul Hudson’s well-renowned course 100 Days Of Swift.

Day 1-5

This is all mostly recap for me since I’m not new to programming but Swift does do a couple things differently. It’s actually closer to Python than I had originally realized. Probably the coolest feature I learned was parameter labels on Day 5. Swift is a bit more explicit and verbose than other languages and this is an example of where writing more code ends up not being a bad thing.

Before we go on, worth mentioning that parameter labels are optional, and you can have one or two but you can’t have 3 or more. So in this function we have 2 parameter labels to and name. The to is used externally (ouside of the function) and name is used in the function. They’re read in left to right order to the leftmost (or first) parameter label is always going to be the external one. The next/second one is the internal.

func sayHello(to name: String) {
    print("Hello, \(name)!")
}

sayHello(to: "Taylor")

So in the function we shouldn’t see to, only name when writing our variables. Outside the function definition, when we’re calling it, we’ll use the first parameter label to in it. We won’t use name externally.

We can also omit labels with an underscore (”_”) like this. So it’s basically just saying we’re using this two-parameter label method but there’s no need to name the first so when we call the function we’ll just pass the string.

func greet(_ person: String) {
    print("Hello, \(person)!")
}

greet("Taylor")

Day 6 & 7

Closures. Probably the thing most devs complain about in the learning process. It seems to stump a lot of people.

Written by Christian Turner
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