let label = "area is "
let width: Double = 30                                          //let은 constant, var은 variable
var height = 20.5                                               //name: datatype = value로 명시적으로 형을 나타내줄 수 있다.
print(label + String(width * height))                           //int는 int끼리만 연산 가능한듯...?
    
height = 40
print(label + String(width * height))                           //출력할 땐 String으로 형변환이 되어야함.
    
print(label + "\(width * height) square meter")                 //backslash를 통해 문자열 안에 변수를 넣을 수 있다.
    
let numberOfOranges = 3
let numberOfApples = 5
    
let comment = """
I got \(numberOfOranges) oranges,
and \(numberOfApples) apples,
so I got total \(numberOfOranges + numberOfApples) fruits!    
"""
    
print(comment)

var shoppingList = [ "apple", "orange", "garlic", ]
print(shoppingList)
shoppingList[2] = "onion"
print(shoppingList)
shoppingList.append("bannana")
print(shoppingList)
print("2nd thing I have to buy is " + shoppingList[2] + "\n");
    
var professionList = [
    "minseok" : "KNCCS",
    "seunghun" : "CERT"
]
print(professionList)
professionList["seunghun"] = "PC Management"
print(professionList)

var scoreList = [97, 88, 0, 25, 43, 63, 55, 72, 38]
var totalScore = 0

for score in scoreList{
    totalScore += score
}
print("you got total \(totalScore) score")
print("your average score is \(totalScore / scoreList.endIndex)")   //end index equals to the size of list

var optional: String? = "seunghun"
//optional = nil
    
if let name = optional{
    print("\nHello, \(name)")
}
else{
    print("\noptional is nil")
}
    
var nickName: String? = "yabby"
var fullName = "Seunghun Yang"

print("Hi, \(nickName ?? fullName)")        //conditional print

var vegetable = "bacon"
    
switch vegetable{                                                   //no need to break for separating each cases
case "cucumber":
    print("I hate cucumber")
case "lettuce", "tomato", "bacon":                                  //, works like or
    print("\nLet's make some BLT sandwiches")
default:
    print("\nLet's go get some")                                    //default is needed
}

var classInfo = [
    1 : [188, 172, 165, 157],
    2 : [192, 183, 171, 162],
    3 : [165, 168, 173, 176]
]
    
var tallestHeight = 0
for (classNumber, heights) in classInfo{
    for height in heights{
        //print("finding \(classNumber)")                           //search begins random point
        if height > tallestHeight{
            tallestHeight = height
            print("tallest height found in \(classNumber), new tallest height is \(height)")
        }
    }
}

var i = 0
    
while i < 9{
    print("Hello \(i)")
    i += 1
}
    
print()
var sum = 0
    
for i in 0..<11{                        //can't use <=
    sum += i
}
    
print("sum of 0 to 10 is \(sum)")

func greet(fullName: String, nickName: String?){
    print("Hello, \(nickName ?? fullName)")
}
    
func greet2(_ fullName: String, _ nickName: String?){
    print("Hello, \(nickName ?? fullName)")
}
    
greet(fullName : "seunghun", nickName: nil)                         //must use labels with parameter when call function
greet2("kiyoung", "kkiyo")                                          //when you declare func, if you add _ before parameter, you can call without labels

func scoreStatistics(_ scores: [Int]) -> (min: Int, max: Int, tot: Int, avg: Int){
    var min = 100
    var max = 0
    var tot = 0
    var avg = 0;
        
    for score in scores{
        tot += score
        if score < min{
            min = score
        }
        else if score > max{
            max = score
        }
    }
        
    avg = tot / scores.endIndex
    
    return (min, max, tot, avg)
}
    
var scoresOfMidterm = [97, 66, 57, 87, 33, 29]
let midtermStatistics = scoreStatistics(scoresOfMidterm)

print("your midterm scores : \(scoresOfMidterm)")
print("midterm statistics : your best score is \(midtermStatistics.max), lowest score is \(midtermStatistics.min), total score is \(midtermStatistics.tot), averages score is \(midtermStatistics.avg)")