💾 Archived View for gem.sdf.org › s.kaplan › cheatsheets › programming-languages › swift.md captured on 2024-08-31 at 12:51:31.

View Raw

More Information

⬅️ Previous capture (2023-09-28)

-=-=-=-=-=-=-

# Swift Cheatsheet

This cheatsheet provides an overview of Swift's unique features and includes code blocks for variables, functions, loops, conditionals, file manipulation, and more. 

## Variables

Declaring a variable:

var myVariable = "Hello, world!"


Declaring a constant:

let myConstant = 42


## Functions

Declaring a function:

func greet(person: String) -> String {

let greeting = "Hello, " + person + "!"

return greeting

}


Calling a function:

print(greet(person: "John"))


## Loops

For loop:

for index in 1...5 {

print("\(index) times 5 is \(index * 5)")

}


While loop:

var i = 0

while i < 10 {

print(i)

i += 1

}


## Conditionals

If statement:

let temperature = 70

if temperature > 65 {

print("It's warm outside!")

} else {

print("It's cold outside!")

}


Switch statement:

let planet = "Earth"

switch planet {

case "Earth":

print("Mostly harmless")

default:

print("Not a safe place for humans")

}


## File Manipulation

Reading a file:

if let contents = try? String(contentsOfFile: "/path/to/file") {

print(contents)

}


Writing to a file:

let text = "Hello, world!"

if let dir = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first {

let fileURL = dir.appendingPathComponent("file.txt")

do {

try text.write(to: fileURL, atomically: false, encoding: .utf8)

}

catch {

// Handle error

}

}


## Resources

- [The Swift Programming Language](https://docs.swift.org/swift-book/)
- [Swift.org](https://swift.org/)
- [Swift Playgrounds](https://www.apple.com/swift/playgrounds/)