https://github.com/melling/swiftcookbook
Swift Language Cookbook
https://github.com/melling/swiftcookbook
swift-language
Last synced: 12 months ago
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Swift Language Cookbook
- Host: GitHub
- URL: https://github.com/melling/swiftcookbook
- Owner: melling
- License: cc0-1.0
- Created: 2016-10-06T14:05:43.000Z (over 9 years ago)
- Default Branch: master
- Last Pushed: 2020-10-08T13:48:13.000Z (over 5 years ago)
- Last Synced: 2025-03-24T01:35:13.571Z (over 1 year ago)
- Topics: swift-language
- Language: Swift
- Homepage: http://www.h4labs.com/dev/ios/swift_cookbook.html
- Size: 131 KB
- Stars: 56
- Watchers: 5
- Forks: 4
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# h4labs Swift Cookbook
This content will (eventually) be mirrored on my site: http://www.h4labs.com/dev/ios/swift_cookbook.html
This repo will be mainly about the Swift language. I have another [repo with small iOS projects](https://github.com/melling/ios_topics/blob/master/README.md)
Swift 5.x compatible
- [Basics](README.md) | [Colors](color.md) | [Date and Time](Dates/README.md) | [Sorting](sorting.md) | [Strings](strings.md) | [Functional Swift](functional.md)
- Collections: [Arrays](array.md) | [Dictionaries](dictionary.md) | [Sets](sets.md) |
## Variable Declarations
Common types: **Int**, **String**, **Bool**, **CGFloat**, **Double**, **Float**
**let** is used to declare immutable values, while **var** is used to declare mutable variables.
```swift
let language = "Swift" // Immutable String
var i = 0 // mutable Int
i += 1
var x:CGFloat = 2
var name:String
let max:Int
max = 99
var isDone = false // Bool
```
## if
```swift
let fuel = 9
let msg:String // Must assign in all cases
if fuel < 10 {
msg = "Fuel dangerously low: \(fuel)"
} else if fuel < 50 {
msg = "Fuel low: \(fuel)"
} else {
msg = "Fuel OK"
}
```
## ternary operator
```swift
let color = Bool.random() ? "red" : "black"
```
## switch
```swift
switch ticker {
case "AAPL":
case "GOOGL":
case "MSFT":
default:
}
```
## for
```swift
for i in 0..<10 {
print("\(i)")
}
for i in 0...9 {
print("\(i)")
}
```
## for enumeration
```swift
for company in ["Apple", "Google", "Microsoft"] {
print("\(company)")
}
```
## function declarations
```swift
func add1(i:Int) -> Int { i + 1 } // return word not needed if we have 1 expression
let r0 = add1(i: 1) // 2
```
Same function but add _ to not need a named parameter
```swift
func add1(_ i:Int) -> Int { i + 1 } // return word not needed if we have 1 expression
let r0 = add1(1) // 2
```
```swift
```
### Multiple return values using tuples
```swift
func bestLanguage() -> (String, Int) {
return ("Swift", 1)
}
let (language, rank) = bestLanguage()
```
## Randomness
```swift
let rnd = Int.random(in: 0...1) // 0 or 1
Bool.random() // true or false
Int.random(in: 20...29) // Random in range 20 through 29
Float.random(in: 0...1) // Random between 0 and 1
[1,2,3].randomElement() // random Array element
Set([1,2,3]).randomElement() // random Set element
```
### Shuffle
Sometimes, it's better to shuffle an Array then simply iterate of the result to get a random element. This allows each element to be chosen at random exactly once.
```swift
let shuffled = [1,2,3].shuffled()
```
## enum