Cheatsheet Swift - Storage

May 12, 2019
swift cheatsheet

Storage

This cheat sheet for Swift 5 contains information on ways to store data in memory and some common operations done using the data along with their corresponding outputs.

Variables

Binary

Declaration
var binary: Bool = true
print(binary)

true

Operations
Complement
var binary: Bool = true
print(!binary)

false

And
var binaryA = true
var binaryB = false
print(binaryA && binaryB)

false

Or
var binaryA = true
var binaryB = false
print(binaryA || binaryB)

true

Numbers

Declaration
var number: Int = 1           
var number: Float = 1.0
var number: Double = 1.0
Operations
Add
var numberOne = 20
var numberTwo = 80
print(numberOne + numberTwo)

100

Sub
var numberOne:Float = 102.102
var numberTwo:Float = 2.102
print(numberOne - numberTwo)

100.0

Mul
var numberOne:Double = 1.2
var numberTwo:Double = 1.2
print(numberOne * numberTwo)

1.44

Div
var numberOne:Double = 25
var numberTwo:Double = 2
print(numberOne / numberTwo)

12.5

Conversion
var number:Int? = Int("1")
var number:Float? = Float("1.0")
var number:Double? = Double("1.0")

Text

Declaration
var word = "Julius"
var character: Character = "A"
Operations
Equality Check
var nameOne = "Canute"
var nameTwo = "Canute"
var isEqual = nameOne == nameTwo
print(isEqual)

true

var nameOne = "Julius"
var nameTwo = "Canute"
var isNotEqual = nameOne != nameTwo
print(isNotEqual)

true

var nameOne = "Julius"
var nameTwo = "julius"
var isEqual = nameOne.caseInsensitiveCompare(nameTwo) == .orderedSame
print(isEqual)

true

Access Character
var text = "Julius Canute"
var character = text[text.index(text.startIndex,offsetBy: 7)]
print(character)

C

Substring
var text = "Julius Canute"
var start = text.index(text.startIndex, offsetBy: 0)
var end = text.index(text.startIndex, offsetBy: 6)
var substring:Substring = text[start..<end]
var firstName = String(substring)
print(firstName) 

Julius

Concatenation
var textOne = "Julius"
var textTwo = "Canute"
var text = textOne + " " + textTwo

Julius Canute

Conversion
var numberOne:Int = 1
var numberTwo:Float = 2.0
var numberThree:Double = 3.0
var combinedString = "\(numberOne) \(numberTwo) \(numberThree)"
print(combinedString)

1 2.0 3.0

var text:String = String(numberOne)
print(text)

1

Size
var text = "Julius Canute"
print(text.length)

13

var text = ""
print(text.isEmpty)

true

Containers

Array

Declaration
var data:Int = [Int]()
var data:[Int] = [1,2,3,4]
Operations
Access Element
var data:[Int] = [1,2,3,4]
print(data[0])

1

Add Element
var data:[Int] = [1,2,3,4]
data.append(5)
print(data[4])

5

var data:[Int] = [1,2,3,4]
data.insert(0,at:0)
print(data[0])

0

Delete Element
var data:[Int] = [1,2,3,4]
data.remove(at:0)
print(data[0])

2

Collections Size
var data:[Int] = [1,2,3,4]
print(data.count)

4

var data:[Int] = []
print(data.isEmpty)

true

Dictionary

Declaration
var data:[Int: String]=[Int: String]()
var data:[Int: String]=[1:"Julius",2:"Canute"]
Operations
Access Element
var data:[Int: String]=[1:"Julius",2:"Canute"]
print(data[2])

Canute

Add Element
var data:[Int: String]=[1:"Julius",2:"Canute"]
data[3]="A"
print(data[3])

A

Delete Element
var data:[Int: String]=[1:"Julius",2:"Canute"]
data.removeValue(forKey: 1)
print(data[1])

nil

Contains Key
var data:[Int: String]=[1:"Julius",2:"Canute"]
data.removeValue(forKey: 1)
var keyExists = data[1] != nil
print(keyExists)

false

Collections Size
var data:[Int: String]=[1:"Julius",2:"Canute"]
print(data.count)
//Output: 2
var data:[Int: String]=[Int: String]()
print(data.isEmpty)

true

Set

Declaration
var data:Set<Int> = Set<Int>()
print(data.count)

0

var data:Set<Int> = [1,2,3,1]
print(data.count)

3

Operations
Add Element
var data:Set<Int> = Set<Int>()
data.insert(1)
data.insert(2)
data.insert(1)
print(data.count)

2

Delete Element
var data:Set<Int> = Set<Int>()
data.insert(1)
data.insert(2)
data.remove(1)
print(data.count)

1

Contains Key
var data:Set<Int> = Set<Int>()
data.insert(1)
data.insert(2)
data.remove(1)
var keyExists = data.contains(1)
print(keyExists)

false

Collections Size
var data:Set<Int> = Set<Int>()
print(data.isEmpty)

0

var data:Set<Int> = [1,2,3,1]
print(data.count)

3

Constants

Declaration
let binary: Bool = true
let binary: Bool = false
let number: Int = 1           
let number: Float = 1.0
let number: Double = 1.0
let word = "Julius"
let character: Character = "A"
let data:[Int] = [1,2,3,4]
let data:[Int: String]=[1:"Julius",2:"Canute"]
let data:Set<Int> = [1,2,3,1]
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