Swift Functions Part One

Swift Functions Part One.swift

import UIKit

/*

    Swift Functions on theswift.ninja!
    http://www.theswift.ninja/swift/
*/

//Function of type Void (doesn't not return nothing)

func addition(a:Int, b:Int){
    
    print("\(a+b)")
}

addition(2, 2)


//Function of type Int
func addition2(a:Int, b:Int) -> Int {
    return a+b
}

addition2(2, 3)

//Function of type Int
func addition3(a:[Int]) -> Int {
    
    var sum:Int = 0
    
    for i in a {
        sum += i
    }
    return sum
}

var evenNumbers = [2,4,6,8,10]
addition3(evenNumbers)
addition3([1,2,3,4])

//Function of type Int
func addition4(a:Int... ) -> Int {
    
    return addition3(a)
}

addition4(1,2,3,4,5)

//Function type Function (it returns another function)
func addition5(a:Int, b:Int) -> () -> Int {
    return {c in a + b}
}

let sum = addition5(3,3)

sum()

//Curring

func additon6(x: Int) -> (Int -> Int) {
    return { y in return x + y }
}

let res = additon6(5)(6)

//Wildcard pattern
func addition7(_ a:Int = 0, _ b:Int = 0){
    
    print("\(a+b)")
}

addition7(1, 3)

//Functions of type Int that recieves functions as parameters
func operate (a:Int, b:Int, fn:(Int, Int)->Int) {
    
    fn(a,b)
}

var add: (Int, Int) -> Int = {
    return $0 + $1
}

let result = add(4,5)
result

//Error a is let type
func operate3(a:Int) -> Int {

    return a + 1
}

func operate4(var a:Int) -> Int {
    a++
    return a
}

operate4(3)

operate(1,2,{ (a:Int, b:Int)->(Int) in return a+b })

operate(1,2,{(a, b)->(Int) in return a+b })

operate(1,2,{(a, b) in a+b })

operate(1,2){ $0+$1 }

operate4(5)

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