Kolleksiya amallari

fun main() {
    val sonlar = listOf(4, 17, 8, 23, 15, 42)

    println(sonlar.map { it * 2 })
    println(sonlar.filter { it > 10 })
    println(sonlar.filter { it % 2 == 0 }.map { it / 2 })
    println(sonlar.filterNot { it > 10 })
}

fun main() {
    val ismlar = listOf("malika", "husanboy", "aziza")

    println(ismlar.map { it.replaceFirstChar { c -> c.uppercase() } })
    println(ismlar.map { ism -> ism.length })
    println(ismlar.filter { ism -> ism.startsWith("a") })
}

fun main() {
    val shaharlar = listOf("Namangan", "Andijon", "Farg'ona")

    shaharlar.forEach { println("- $it") }

    shaharlar.forEachIndexed { i, shahar ->
        println("$i: $shahar")
    }
}

fun main() {
    val ballar = listOf(88, 92, 75, 95, 61)

    println(ballar.size)
    println(ballar.sum())
    println(ballar.average())
    println(ballar.max())
    println(ballar.min())
    println(ballar.count { it >= 85 })
    println(ballar.sumOf { it * 2 })
}

fun main() {
    val ballar = listOf(88, 92, 75, 95, 61)

    println(ballar.any { it > 90 })
    println(ballar.all { it >= 60 })
    println(ballar.none { it < 50 })

    val bosh = emptyList<Int>()
    println(bosh.any { it > 0 })
    println(bosh.all { it > 0 })
}

fun main() {
    val sonlar = listOf(4, 17, 8, 23, 15)

    println(sonlar.first())
    println(sonlar.first { it > 10 })
    println(sonlar.find { it > 100 })
    println(sonlar.firstOrNull { it > 100 })
    println(sonlar.last { it < 20 })
    println(sonlar.indexOfFirst { it > 10 })
}

fun main() {
    val ismlar = listOf("Nodira", "Aziza", "Husanboy", "Malika")

    println(ismlar.sorted())
    println(ismlar.sortedDescending())
    println(ismlar.sortedBy { it.length })
    println(ismlar.sortedByDescending { it.length })
    println(ismlar.reversed())

    val sonlar = listOf(3, 1, 4, 1, 5)
    println(sonlar.sorted())
}

data class Talaba(val ism: String, val ball: Int)

fun main() {
    val talabalar = listOf(
        Talaba("Malika", 88),
        Talaba("Husanboy", 92),
        Talaba("Aziza", 95)
    )

    println(talabalar.maxByOrNull { it.ball })
    println(talabalar.minByOrNull { it.ball })
    println(talabalar.maxOf { it.ball })
    println(talabalar.sortedByDescending { it.ball }.map { it.ism })
}

data class Talaba(val ism: String, val ball: Int, val guruh: String)

fun main() {
    val talabalar = listOf(
        Talaba("Malika", 88, "A"),
        Talaba("Husanboy", 92, "B"),
        Talaba("Nodira", 75, "A"),
        Talaba("Aziza", 95, "B"),
        Talaba("Kamola", 61, "A")
    )

    val guruhlar = talabalar.groupBy { it.guruh }
    println(guruhlar.keys.sorted())

    for (kalit in guruhlar.keys.sorted()) {
        val a = guruhlar[kalit]!!
        val ortacha = a.map { it.ball }.average()
        println("$kalit: ${a.size} talaba, o'rtacha $ortacha")
    }

    println(talabalar.groupBy { it.guruh }.mapValues { it.value.size })
}

data class Talaba(val ism: String, val ball: Int)

fun main() {
    val talabalar = listOf(
        Talaba("Malika", 88),
        Talaba("Husanboy", 92)
    )

    println(talabalar.associate { it.ism to it.ball })
    println(talabalar.associateBy { it.ism })
    println(talabalar.associateWith { it.ball > 90 })
}

fun main() {
    val sonlar = listOf(1, 2, 3, 4, 5)

    println(sonlar.reduce { a, b -> a + b })
    println(sonlar.fold(0) { a, b -> a + b })
    println(sonlar.fold(100) { a, b -> a + b })
    println(sonlar.fold("") { a, b -> "$a$b" })
    println(sonlar.reduce { a, b -> a * b })
}

fun main() {
    val sonlar = listOf(1, 2, 3, 4, 5, 6, 7, 8)

    println(sonlar.take(3))
    println(sonlar.drop(5))
    println(sonlar.takeWhile { it < 4 })
    println(sonlar.dropWhile { it < 4 })
    println(sonlar.takeLast(2))
    println(sonlar.chunked(3))
    println(sonlar.windowed(3))
}

fun main() {
    val ismlar = listOf("Malika", "Husanboy", "Aziza")
    val ballar = listOf(88, 92, 95)

    println(ismlar.zip(ballar))
    println(ismlar.zip(ballar) { i, b -> "$i: $b" })

    val guruhlar = listOf(listOf(1, 2), listOf(3, 4), listOf(5))
    println(guruhlar.flatten())
    println(guruhlar.flatMap { it.map { x -> x * 10 } })
}

data class Mahsulot(val nom: String, val narx: Int, val soni: Int)

fun main() {
    val ombor = listOf(
        Mahsulot("Olma", 12000, 40),
        Mahsulot("Anor", 18000, 15),
        Mahsulot("Uzum", 22000, 8),
        Mahsulot("Shaftoli", 9500, 0)
    )

    val hisobot = ombor
        .filter { it.soni > 0 }
        .sortedByDescending { it.narx * it.soni }
        .map { "${it.nom}: ${it.narx * it.soni}" }

    hisobot.forEach { println(it) }

    println("Jami: ${ombor.sumOf { it.narx * it.soni }}")
    println("Tugagan: ${ombor.filter { it.soni == 0 }.map { it.nom }}")
}