100 Days of SwiftUI - Day 2

Second post in my #100DaysOfSwiftUI journey. Here’s some stuff I learned (at https://www.hackingwithswift.com/100/swiftui/2):

Note: I’m going to make these posts shorter because I think it is distracting me from actually learning. I’m spending so much time getting the formatting right and such, and not as much time learning. I think I will only learn this stuff by actually using it (like any language), so I think the quicker I get to the point where I get ideas about things I can do and then can look up how to do it, the better.

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Quotes inside strings

You can include quotes inside strings as long as you put a backslash \ before the quote. i.e.

let quote = "Then he tapped a sign saying \"Believe\" and walked away."

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String interpolation

Usually you can’t add integers with strings and vice versa, but Swift does let you if you tell it to treat an integer as a string, with this method:

let number = 11

let missionMessage = "Apollo " + String(number) + " landed on the moon"

But using string interpolation is more efficient:"

let number = 11

let missionMessage = "Apollo \(number) landed on the moon"

But you can’t include both in the same project (with the same constants anyway), I found.

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My first app lol

Note: Paul Hudson wanted me to pay for a video that showed me how to code my first app. He lied because he said the course was free. Yeah. Write the course in such a way where there’s no way the student is going to be able to complete the assignment, even with the hints you provided. Lame. I just used ChatGPT haha. I’m not giving money to a sneaky liar.

This app starts with defining a temperature in Celsius then converts it to Fahrenheit by:

• multiplying by 9

• dividing by 5

• and adding 32

import Cocoa

let celsius: Double = 30.0
let fahrenheit = (celsius * 9 / 5) + 32

print("\(celsius)°C is equal to \(fahrenheit)°F")

Things to note:

Celsius temperatures often contain decimal points, so we use the Double type to ensure precise calculations. This makes sense because:

• Double allows decimal values, unlike Int, which only handles whole numbers.

• Using Double prevents unintended rounding errors when performing calculations like multiplication and division.

Here’s how it looks in Xcode:

Exploring Strings

I also explored different ways to work with strings in Swift:

• Declaring and Printing Strings

• Escaping Quotes Inside Strings

• Using String Interpolation to Insert Variables

• Combining Numbers and Strings in Interpolation

The image below shows my Swift Playground where I experimented with these concepts:

Appending to arrays and printing count

var albums = ["Pretty Hate Machine"] // Initialize an array with one element
albums.append("Broken") // Append another album
albums.append("The Downward Spiral") // Append a third album

print(albums.count) // Expected output: 3

I learned that without the [ and ] around “Pretty Hate Machine”, it would not create an array, and print(albums.count) would result in a count of the numbers of characters in all 3 album names combined, instead of how many albums in the array, which would be 3 as shown above.

Arrays

Lastly, I explored:

• Checking if an Array Contains an Element

• Sorting an Array in Ascending Order

• Counting Elements in an Array

• Removing an Element from an Array

• Removing All Elements from an Array

• Reversing an Array in Swift

• Using reversed() (Lazy Reversal)

• Converting a Reversed Collection to an Array