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]