Category: Swift / SwiftUI

import UIKit
import Foundation

var funWithStrings = UIImage(named:"kittenWithOrangeString.jpg"):

let myFirstString = "no "
let mySecondString = "no problems"

let theTruth = myFirstString + ", " + mySecondString

var doggyDiet = "Lulu eats 25lbs of dog food per month"
var dogName = "Ferris"
var ferrisPic = UIImage(named:"SpringerdoodleFerris.jpg")

var lbsPerDay = 0.75
var daysPerMonth:Double = 30.0
doggyDiet = "\(dogName) eats \(lbsPerDay * daysPerMonth) of dog food per month"

var frankiePic = UIImage(named:"frankie.jpeg")!
lbsPerDay = 0.25
dogName = "Lil Frankie"
doggyDiet = "\(dogName) eats \(lbsPerDay * daysPerMonth) of dog food per month"

access an array of characters

var password = "Meet me in St. Louis"
for character in password.characters {
	if character == "e" {
		print("found an e!")
	} else {
		
	}
}

if hungry && !vegetarian {
	println("Let's eat steak!")
} else if hungry && vegetarian {
	println("How about pumpkin curry?")
} else {
	println("nevermind")
}

var thereIsPie = true
if hungry || thereIsPie {
	println("Let's eat!")
} else {
	println("Let's wait.")
}

Ternary conditional

if question {
	answer1
} else {
	answer2
}

hugry ? println("Let's eat!") : println("Let's wait.")
hugry || thereIsPie ? println("Let's eat!") : println("Let's wait.")

import UIKit
import Foundation

class LightSwitch {
	var on: Bool = true
}

var livingRoomSwitch = LightSwitch()
livingRoomSwitch.on

var dollarSign: Character = "$"
var myFirstSwiftString String = "no' money"

Optional and Tuples

let kitchenSwitch = LightSwitch()
let ticketPrice = 13.75
let swiftIsFast = true
let encouragement = “You can do it!”

let ticketPrice = 7.5
let allowance = 10.0
var iceCreamPrice = 3.0

var pic UIImage(named:"Choe.png")!

if allowance >= ticketPrice + iceCreamPrice {
	println("Let's go to the movies!")
} else {
	println("Let's watch a movie at home and eat ice cream")
}

var hungry = true
var vegetarian = false

if hungry {
	println("Let's eat!")
} else {
	println("Let's wait.")
}

Y = ax + b
stackView seen same screen

Compression Resistance
Label, TextField, Button, Slider, ImageView

Intrinsic Content Size
Compression Resistance
Content Hugging

-stack view
axis, spacing, alignment, distribution

happily modifies size of view
-> fill(default), fill equally, fill proportionally

works hard not to modify size of views
->equal spacing, equal centering

alignment -horizontal stack views
text-> ascender, baseline, descender

guiding principles of autolayout
-stackView first, constraints later
-Start small, or not at all
-Work from the inside out
-Trust the simulator only
-Don’t panic

Seven Commandments of AutoLayout
1. Tweak the properties of the StackView
2. Use another StackView
3. Tweak the compression resistance or the hugging priority
4. Add constraints to the StackView
5. Add constraints to the views
6. To connect views within different StackViews, use V.
7. If everything else fails, use a filler view

-Laying out the views
-Deciding how these views will adapt when the available screen size changes

import UIKit

class CodeViewController:
	UIViewController {

	override func loadView(){
		code
	}
}

-screen size changes
iphone se, iphone 6+
rotaion

code, xibs, storyboards

-Swift Code(NSLayoutConstraint)
-Visual Format Code
-Creating constraints in IB

UIStackView

create a project
add views
define layouts
integrate functions
connect ui to code
respond to events

func firstCharacter(of word: String) -> Character {
	return word[word.startIndex]
}

firstCharacter(of: "Mom")

import Fundation

func placeFirstLetterLast(myString: String){
	
}

func placeFirstLetterLast (myString: String) -> String {
	var myString = myString
	myString.append(firstCharacter(of: myString))
	return myString
}
func shortNameFromName(name: String) -> String {
	let lowercaseName = name.lowercaseString
	let vowelSet = CharacterSet(charactersIn: "aeiou")
}

shortNameFromName(name: "Nate")
//
shortNameFromName(name: "Talia")
//

func lyricsForName(lyricsTemplate: String, fullName: String) -> String {
	let shortName = shortNameForName(name: fullName)

	let lyrics = lyricsTemplate
		.replacingOccurrences(of: "<FULL_NAME>", with: fullName)
		.replacingOccurrences(of: "<SHORT_NAME>", with: shortName)

	return lyrics
}

The function print, min, max, and abs are a few examples of global functions. Check out a complete list of Swift’s global functions.

print("I'm a global function!")

var initialPrice = 50
var bestOffer = 45
var finalPrice = min(bestOffer, initialPrice)

Anatomy of a function

func functionName (_ parameterName: parameterType) -> returnType {
	statements to execute
	return object
}

func sumOfStrings(_ aBunchOfStrings: [String]) -> Int {
	let array = aBunchOfStrings
	var sum = 0
	for string in array {
		if Int(string) != nil {
			let int intToAdd = Int(string)!
			sum += intToAdd
		}
	}
	return sum
}

func reverse(_ string: String) -> String {
	var reversedString = ""
	for character in string.characters {
		reversedString = "\(character)" + reversedString
	}
	return reversedString
}

func warmUp(temperature: Int) -> Int {
	return temperature + 10
}
func firstChar(word: String) -> Character {
	return word[word.startIndex]
}

func concatenate(firstString: String, secondString secondString){
	return firstString + secondString
}
func warmUp(temperature: Int) -> Int {
	return temperature + 10
}
func firstCharacter(word: String) -> Character {
	return word[word.startIndex]
}
func concatenate(firstString: String, secondString: String)-> String {
	return firstString + secondString
}

var lightSwitchOn: Bool = true
var dimmer: Int = 7
var dimmerWithDecimals: Float = 3.14
var veryPreciseDimmer: Double = 3.14159265359

print(type(of: lightSwitchOn))
print(type(of: veryPreciseDimmer))

Bool
Double

Double, Bool, String, Float

use let to declare a constant when we expect its value to remain the same
we expect let not change

let encouragement = "You can do it!"

var personalizedEncouragement = "You can do it, Stephanie!"
personalizedEncouragement = personalizedEncouragement.replacingOccurrences(of: "Stephanie", with: "Ryder")

let birthYear = 2008
var currentYear = 2016
var age = currentYear - birthYear
age = currentYear - birthYear