magdamiu

var priceBooks = 0.0
val prefixPriceDetails = "The current sum is "
books.forEach {
    priceBooks += it.price
    println("$prefixPriceDetails $priceBooks")
}

magdamiu

fun titleStartsWithS(book: Book) = book.title.startsWith("S")
fun lengthOfTitleGraterThan5(book: Book) = book.title.length > 5
fun authorStartsWithB(book: Book) = book.author.startsWith("B")

val book1 = Book("Start with why", "Simon Sinek")
val book2 = Book("Dare to lead", "Brene Brown")
val books = listOf(book1, book2)

// this code should be improved
val filteredBooks = books

magdamiu

class Book(val title: String, val author: String) {
    // impure function
    fun getBookDetails() = "$title - $author"
}

// pure function
fun getBookDetails(title: String, author: String) = "$title - $author"

magdamiu

val <T> T.exhaustive: T
    get() = this
    
fun displayMovieResult(movieResult: MovieSearchResult) {
    when(movieResult) {
        is MovieFound -> println("yey, we found the movie")
        is MovieNotFound -> TODO()
    }.exhaustive
}

magdamiu

sealed class MovieSearchResult
data class MovieFound(val movie: Movie) : MovieSearchResult()
object MovieNotFound : MovieSearchResult()
object DatabaseOffline : MovieSearchResult()

fun displayMovieResult(movieResult: MovieSearchResult) {
    when(movieResult) {
        is MovieFound -> println("yey, we found the movie")
        is MovieNotFound -> TODO()
    }

magdamiu

fun computeSqrt(number: Double): Double {
    if(number >= 0) {  
        return Math.sqrt(number)
    } else {  
        throw RuntimeException("No negative please")
    }
}

magdamiu

var countUsersYoungerThan30WithSubscriptions = 0
for (user in users) {
    if (user.isYoungerThan30WithSubscriptions) {
        countUsersYoungerThan30WithSubscriptions++;
    }
}

magdamiu

for (user in users) {
    if(user.subscriptions != null) {
        if (user.subscriptions.size > 0) {
            var isYoungerThan30 = user.isYoungerThan30()
            if (isYoungerThan30) {
                countUsers++
            }
        }
    }
}

magdamiu

fun parseProduct(response: Response?) = when (response?.code()){
    null -> throw ClientException("Response is null")
    200, 201 -> mapToDTO(response.body())
    in 400..499 -> throw ClientException("Invalid request")
    in 500..599 -> throw ClientException("Server error")
    else -> throw ClientException("Error ${response.code()}")
}

magdamiu

fun parseProduct(response: Response?): Product? {
    if (response == null) {
        throw ClientException("Response is null")
    }
    val code: Int = response.code()
    if (code == 200 || code == 201) {
        return mapToDTO(response.body())
    }
    if (code >= 400 && code <= 499) {
        throw ClientException("Invalid request")