Get warmed up to code in Swift

practice.swift

// comment

/* multi-line
comment */

let x = true
var y = false
let z = 1
var o: String?

if x {
    print("if")
} else if y {
    print("else if")
} else {
    print("else")
}

switch z {
case 1:
    print("1")
case 2:
    print("2")
default:
    print("not 1 or 2")
}

if o != nil {
    print("do something")
}

if let something = o {
    print("\(something) is not nil")
}

var someStrings = [String]()
someStrings.append("Hello")

for string in someStrings {
    print(string)
}

for i in 1...100 {
    print(i)
}

for i in 1..<100 {
    print(i)
}

func add(_ a: Int, _ b: Int) -> Int {
    return a + b
}

let result = add(3,4)