Fayllar bilan ishlash

import java.io.File

fun main() {
    val fayl = File("qaydlar.txt")

    fayl.writeText("Birinchi qator\nIkkinchi qator")
    println(fayl.readText())

    fayl.appendText("\nUchinchi qator")
    println("---")
    println(fayl.readText())

    fayl.delete()
    println(fayl.exists())
}

import java.io.File

fun main() {
    val fayl = File("talabalar.txt")
    val royxat = listOf("Malika", "Husanboy", "Nodira", "Aziza")

    fayl.writeText(royxat.joinToString("\n"))

    val oqilgan = fayl.readLines()
    println("Jami: ${oqilgan.size}")

    oqilgan.forEachIndexed { i, ism ->
        println("${i + 1}. $ism")
    }

    println(oqilgan.filter { it.startsWith("A") })

    fayl.delete()
}

import java.io.File

fun main() {
    val fayl = File("sonlar.txt")
    fayl.writeText((1..1000).joinToString("\n"))

    val jami = fayl.useLines { qatorlar ->
        qatorlar.map { it.toInt() }.filter { it % 3 == 0 }.sum()
    }
    println("3 ga bo'linadiganlar yig'indisi: $jami")

    var soni = 0
    fayl.forEachLine { soni++ }
    println("Qatorlar: $soni")

    fayl.delete()
}

import java.io.File

fun main() {
    val fayl = File("hisobot.txt")

    fayl.bufferedWriter().use { yozuvchi ->
        yozuvchi.write("Sarlavha")
        yozuvchi.newLine()
        repeat(3) { i ->
            yozuvchi.write("Qator ${i + 1}")
            yozuvchi.newLine()
        }
    }

    fayl.bufferedReader().use { oquvchi ->
        println(oquvchi.readText().trim())
    }

    fayl.delete()
}

import java.io.File

fun main() {
    val papka = File("sinov_papka")
    papka.mkdirs()
    println(papka.exists())

    File(papka, "a.txt").writeText("A")
    File(papka, "b.txt").writeText("B")

    val fayllar = papka.listFiles()?.sortedBy { it.name } ?: emptyList()
    println("Fayllar: ${fayllar.size}")
    fayllar.forEach { println("  ${it.name} (${it.length()} bayt)") }

    papka.deleteRecursively()
    println(papka.exists())
}

import java.io.File

fun main() {
    val fayl = File("hujjatlar/hisobot.pdf")

    println(fayl.name)
    println(fayl.nameWithoutExtension)
    println(fayl.extension)
    println(fayl.parent)
    println(fayl.path.replace("\\", "/"))
}

import java.io.File

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

fun oqi(fayl: File): List<Talaba> =
    fayl.readLines()
        .drop(1)
        .filter { it.isNotBlank() }
        .mapNotNull { qator ->
            val qismlar = qator.split(",").map { it.trim() }
            if (qismlar.size != 3) return@mapNotNull null
            val ball = qismlar[1].toIntOrNull() ?: return@mapNotNull null
            Talaba(qismlar[0], ball, qismlar[2])
        }

fun main() {
    val fayl = File("talabalar.csv")
    fayl.writeText(
        """
        ism,ball,guruh
        Malika,88,A
        Husanboy,92,B
        Nodira,xato,A
        Aziza,95,B
        """.trimIndent()
    )

    val talabalar = oqi(fayl)
    println("O'qildi: ${talabalar.size} ta")
    talabalar.forEach { println("  $it") }

    println("O'rtacha: ${talabalar.map { it.ball }.average()}")

    fayl.delete()
}

import java.io.File

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

fun main() {
    val ombor = listOf(
        Mahsulot("Olma", 12000),
        Mahsulot("Anor", 18000),
        Mahsulot("Uzum", 22000)
    )

    val fayl = File("ombor.csv")

    fayl.bufferedWriter().use { w ->
        w.write("nom,narx")
        w.newLine()
        ombor.forEach {
            w.write("${it.nom},${it.narx}")
            w.newLine()
        }
    }

    println(fayl.readText().trim())

    fayl.delete()
}

import java.io.File

fun xavfsizOqi(yol: String): String {
    val fayl = File(yol)
    if (!fayl.exists()) return "Fayl topilmadi: $yol"
    return runCatching { fayl.readText() }
        .getOrElse { "O'qib bo'lmadi: ${it::class.simpleName}" }
}

fun main() {
    val fayl = File("bor.txt")
    fayl.writeText("mazmun")

    println(xavfsizOqi("bor.txt"))
    println(xavfsizOqi("yoq.txt"))

    fayl.delete()
}