Swift Cheatsheet

2023-08-21 268 words 2 minutes

Contents

Basics
OOP

Basics

Data Types

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 let intVar : Int = 10
 let doubleVar : Double = 10.5
 let boolVar : Bool = true
 let stringVar : String = "Hello, World!"

Conditional Statements

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if boolVar {
   print("It is True!")
} else{
   print("It is False!")
   }

Loops

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   //for loops:
   for i in range 1...5 {
       print(i)
   }
   //while loops:
   i = 0
   while i < 5 {
       print(i)
       i += 1
   }

Use let for constants and var for variable (Using let is always a good idea)
Functions

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    // like go, first comes with variable name,then comes after with data type
    func add(a Int,b Int) -> Int {
        return a + b;
    }

OOP

Constructor or Initializer:

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class Car: Vehicle {
    var color: String

    init(wheels: Int,color: String) {
        self.color = color
        super.init(wheels: wheels)
    }

    convenience init() {
        self.init(wheels: 4, color: "Red")
    }
}

let myCar = car() // use convenience init

Protocols (similar to interface in Java)

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protocol Runnable {
    func run()
}

class Human: Runnable {
    func run() {
    print("Human runs on two legs")
    }
}

class Cheetah: Runnable {
    func run() {
    print("Cheetah runs very fast!")
    }
}

Extensions

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extension Int {
 var squared: Int {
     return self * self
     }
 }

let fourSquared = 4.squared  // Outputs: 16