Kotlin에서 클래스 및 객체 사용

val number: Int = 1

fun main() {
}

class SmartDevice {
    // empty body
}

fun main() {
}

fun main() {
    val smartTvDevice = SmartDevice()
}

class SmartDevice {
    fun turnOn() {

    }
}

class SmartDevice {
    fun turnOn() {
        println("Smart device is turned on.")
    }
}

class SmartDevice {
    fun turnOn() {
        println("Smart device is turned on.")
    }

    fun turnOff() {
        println("Smart device is turned off.")
    }
}

class SmartDevice {
    fun turnOn() {
        // A valid use case to call the turnOff() method could be to turn off the TV when available power doesn't meet the requirement.
        turnOff()
        ...
    }

    ...
}

fun main() {
    val smartTvDevice = SmartDevice()
    smartTvDevice.turnOn()
}

fun main() {
    val smartTvDevice = SmartDevice()
    smartTvDevice.turnOn()
    smartTvDevice.turnOff()
}

Smart device is turned on.
Smart device is turned off.

class SmartDevice {

    val name = "Android TV"

    fun turnOn() {
        println("Smart device is turned on.")
    }

    fun turnOff() {
        println("Smart device is turned off.")
    }
}

class SmartDevice {

    val name = "Android TV"
    val category = "Entertainment"
    var deviceStatus = "online"

    fun turnOn() {
        println("Smart device is turned on.")
    }

    fun turnOff() {
        println("Smart device is turned off.")
    }
}

fun main() {
    val smartTvDevice = SmartDevice()
    println("Device name is: ${smartTvDevice.name}")
    smartTvDevice.turnOn()
    smartTvDevice.turnOff()
}

Device name is: Android TV
Smart device is turned on.
Smart device is turned off.

var speakerVolume = 2
    get() = field
    set(value) {
        field = value
    }

var speakerVolume = 2
    set(value) {
        field = value
    }

var speakerVolume = 2
    set(value) {
        if (value in 0..100) {
            field = value
        }
    }

class SmartDevice constructor() {
    ...
}

class SmartDevice {
    ...
}

class SmartDevice(val name: String, val category: String) {

    var deviceStatus = "online"

    fun turnOn() {
        println("Smart device is turned on.")
    }

    fun turnOff() {
        println("Smart device is turned off.")
    }
}

SmartDevice("Android TV", "Entertainment")

SmartDevice(name = "Android TV", category = "Entertainment")

class SmartDevice(val name: String, val category: String) {
    var deviceStatus = "online"

    constructor(name: String, category: String, statusCode: Int) : this(name, category) {
        deviceStatus = when (statusCode) {
            0 -> "offline"
            1 -> "online"
            else -> "unknown"
        }
    }
    ...
}

open class SmartDevice(val name: String, val category: String) {
    ...
}

class SmartTvDevice(deviceName: String, deviceCategory: String) :
    SmartDevice(name = deviceName, category = deviceCategory) {
}

class SmartTvDevice(deviceName: String, deviceCategory: String) :
    SmartDevice(name = deviceName, category = deviceCategory) {

    var speakerVolume = 2
        set(value) {
            if (value in 0..100) {
                field = value
            }
        }
}

class SmartTvDevice(deviceName: String, deviceCategory: String) :
    SmartDevice(name = deviceName, category = deviceCategory) {

    var speakerVolume = 2
        set(value) {
            if (value in 0..100) {
                field = value
            }
        }

    var channelNumber = 1
        set(value) {
            if (value in 0..200) {
                field = value
            }
        }
}

class SmartTvDevice(deviceName: String, deviceCategory: String) :
    SmartDevice(name = deviceName, category = deviceCategory) {

    var speakerVolume = 2
        set(value) {
            if (value in 0..100) {
                field = value
            }
        }

     var channelNumber = 1
        set(value) {
            if (value in 0..200) {
                field = value
            }
        }

    fun increaseSpeakerVolume() {
        speakerVolume++
        println("Speaker volume increased to $speakerVolume.")
    }
}

class SmartTvDevice(deviceName: String, deviceCategory: String) :
    SmartDevice(name = deviceName, category = deviceCategory) {

    var speakerVolume = 2
        set(value) {
            if (value in 0..100) {
                field = value
            }
        }

    var channelNumber = 1
        set(value) {
            if (value in 0..200) {
                field = value
            }
        }

    fun increaseSpeakerVolume() {
        speakerVolume++
        println("Speaker volume increased to $speakerVolume.")
    }

    fun nextChannel() {
        channelNumber++
        println("Channel number increased to $channelNumber.")
    }
}

class SmartLightDevice(deviceName: String, deviceCategory: String) :
    SmartDevice(name = deviceName, category = deviceCategory) {
}

class SmartLightDevice(deviceName: String, deviceCategory: String) :
    SmartDevice(name = deviceName, category = deviceCategory) {

    var brightnessLevel = 0
        set(value) {
            if (value in 0..100) {
                field = value
            }
        }
}

class SmartLightDevice(deviceName: String, deviceCategory: String) :
    SmartDevice(name = deviceName, category = deviceCategory) {

    var brightnessLevel = 0
        set(value) {
            if (value in 0..100) {
                field = value
            }
        }

    fun increaseBrightness() {
        brightnessLevel++
        println("Brightness increased to $brightnessLevel.")
    }
}

// Smart TV IS-A smart device.
class SmartTvDevice : SmartDevice() {
}

class SmartLightDevice(deviceName: String, deviceCategory: String) :
    SmartDevice(name = deviceName, category = deviceCategory) {

    ...

}

class SmartHome {
}

fun main() {
    ...
}

// The SmartHome class HAS-A smart TV device.
class SmartHome(val smartTvDevice: SmartTvDevice) {

}

class SmartHome(val smartTvDevice: SmartTvDevice) {

    fun turnOnTv() {
        smartTvDevice.turnOn()
    }
}

class SmartHome(val smartTvDevice: SmartTvDevice) {

    fun turnOnTv() {
        smartTvDevice.turnOn()
    }

    fun turnOffTv() {
        smartTvDevice.turnOff()
    }

}

class SmartHome(val smartTvDevice: SmartTvDevice) {

    fun turnOnTv() {
        smartTvDevice.turnOn()
    }

    fun turnOffTv() {
        smartTvDevice.turnOff()
    }

    fun increaseTvVolume() {
        smartTvDevice.increaseSpeakerVolume()
    }

    fun changeTvChannelToNext() {
        smartTvDevice.nextChannel()
    }
}

class SmartHome(
    val smartTvDevice: SmartTvDevice,
) {

    ...

}

// The SmartHome class HAS-A smart TV device and smart light.
class SmartHome(
    val smartTvDevice: SmartTvDevice,
    val smartLightDevice: SmartLightDevice
) {

    ...

}

class SmartHome(
    val smartTvDevice: SmartTvDevice,
    val smartLightDevice: SmartLightDevice
) {

    ...

    fun changeTvChannelToNext() {
        smartTvDevice.nextChannel()
    }

    fun turnOnLight() {
        smartLightDevice.turnOn()
    }

    fun turnOffLight() {
        smartLightDevice.turnOff()
    }
}

class SmartHome(
    val smartTvDevice: SmartTvDevice,
    val smartLightDevice: SmartLightDevice
) {

    ...

    fun changeTvChannelToNext() {
        smartTvDevice.nextChannel()
    }

    fun turnOnLight() {
        smartLightDevice.turnOn()
    }

    fun turnOffLight() {
        smartLightDevice.turnOff()
    }

    fun increaseLightBrightness() {
        smartLightDevice.increaseBrightness()
    }
}

class SmartHome(
    val smartTvDevice: SmartTvDevice,
    val smartLightDevice: SmartLightDevice
) {

    ...

    fun turnOffAllDevices() {
        turnOffTv()
        turnOffLight()
    }
}

open class SmartDevice(val name: String, val category: String) {

    var deviceStatus = "online"

    open fun turnOn() {
        // function body
    }

    open fun turnOff() {
        // function body
    }
}

class SmartLightDevice(deviceName: String, deviceCategory: String) :
    SmartDevice(name = deviceName, category = deviceCategory) {

    var brightnessLevel = 0
        set(value) {
            if (value in 0..100) {
                field = value
            }
        }

    fun increaseBrightness() {
        brightnessLevel++
        println("Brightness increased to $brightnessLevel.")
    }

    fun turnOn() {
    }
}

    fun turnOn() {
        deviceStatus = "on"
        brightnessLevel = 2
        println("$name turned on. The brightness level is $brightnessLevel.")
    }

class SmartLightDevice(deviceName: String, deviceCategory: String) :
    SmartDevice(name = deviceName, category = deviceCategory) {

    var brightnessLevel = 0
        set(value) {
            if (value in 0..100) {
                field = value
            }
        }

    fun increaseBrightness() {
        brightnessLevel++
        println("Brightness increased to $brightnessLevel.")
    }

    fun turnOn() {
        deviceStatus = "on"
        brightnessLevel = 2
        println("$name turned on. The brightness level is $brightnessLevel.")
    }

    fun turnOff() {
    }
}

class SmartLightDevice(deviceName: String, deviceCategory: String) :
    SmartDevice(name = deviceName, category = deviceCategory) {

    var brightnessLevel = 0
        set(value) {
            if (value in 0..100) {
                field = value
            }
        }

    fun increaseBrightness() {
        brightnessLevel++
        println("Brightness increased to $brightnessLevel.")
    }

    fun turnOn() {
        deviceStatus = "on"
        brightnessLevel = 2
        println("$name turned on. The brightness level is $brightnessLevel.")
    }

    fun turnOff() {
        deviceStatus = "off"
        brightnessLevel = 0
        println("Smart Light turned off")
    }
}

class SmartLightDevice(deviceName: String, deviceCategory: String) :
    SmartDevice(name = deviceName, category = deviceCategory) {

    var brightnessLevel = 0
        set(value) {
            if (value in 0..100) {
                field = value
            }
        }

    fun increaseBrightness() {
        brightnessLevel++
        println("Brightness increased to $brightnessLevel.")
    }

    override fun turnOn() {
        deviceStatus = "on"
        brightnessLevel = 2
        println("$name turned on. The brightness level is $brightnessLevel.")
    }

    override fun turnOff() {
        deviceStatus = "off"
        brightnessLevel = 0
        println("Smart Light turned off")
    }
}

class SmartTvDevice(deviceName: String, deviceCategory: String) : SmartDevice(name = deviceName, category = deviceCategory) {

    var speakerVolume = 2
        set(value) {
            if (value in 0..100) {
                field = value
            }
        }

    var channelNumber = 1
        set(value) {
            if (value in 0..200) {
                field = value
            }
        }

    fun increaseSpeakerVolume() {
        speakerVolume++
        println("Speaker volume increased to $speakerVolume.")
    }

    fun nextChannel() {
        channelNumber++
        println("Channel number increased to $channelNumber.")
    }

    fun turnOn() {
    }
}

class SmartTvDevice(deviceName: String, deviceCategory: String) : SmartDevice(name = deviceName, category = deviceCategory) {

    ...

    fun turnOn() {
        deviceStatus = "on"
        println(
            "$name is turned on. Speaker volume is set to $speakerVolume and channel number is " +
                "set to $channelNumber."
        )
    }
}

class SmartTvDevice(deviceName: String, deviceCategory: String) : SmartDevice(name = deviceName, category = deviceCategory) {

    ...

    fun turnOn() {
        ...
    }

    fun turnOff() {
    }
}

class SmartTvDevice(deviceName: String, deviceCategory: String) : SmartDevice(name = deviceName, category = deviceCategory) {

    ...

    fun turnOn() {
        ...
    }

    fun turnOff() {
        deviceStatus = "off"
        println("$name turned off")
    }
}

class SmartTvDevice(deviceName: String, deviceCategory: String) :
    SmartDevice(name = deviceName, category = deviceCategory) {

    var speakerVolume = 2
        set(value) {
            if (value in 0..100) {
                field = value
            }
        }

    var channelNumber = 1
        set(value) {
            if (value in 0..200) {
                field = value
            }
        }

    fun increaseSpeakerVolume() {
        speakerVolume++
        println("Speaker volume increased to $speakerVolume.")
    }

    fun nextChannel() {
        channelNumber++
        println("Channel number increased to $channelNumber.")
    }

    override fun turnOn() {
        deviceStatus = "on"
        println(
            "$name is turned on. Speaker volume is set to $speakerVolume and channel number is " +
                "set to $channelNumber."
        )
    }

    override fun turnOff() {
        deviceStatus = "off"
        println("$name turned off")
    }
}

fun main() {
    var smartDevice: SmartDevice = SmartTvDevice("Android TV", "Entertainment")
}

fun main() {
    var smartDevice: SmartDevice = SmartTvDevice("Android TV", "Entertainment")
    smartDevice.turnOn()
}

Android TV is turned on. Speaker volume is set to 2 and channel number is set to 1.

fun main() {
    var smartDevice: SmartDevice = SmartTvDevice("Android TV", "Entertainment")
    smartDevice.turnOn()

    smartDevice = SmartLightDevice("Google Light", "Utility")
    smartDevice.turnOn()
}

Android TV is turned on. Speaker volume is set to 2 and channel number is set to 1.
Google Light turned on. The brightness level is 2.

open class SmartDevice(val name: String, val category: String) {

    var deviceStatus = "online"

    open fun turnOn() {
        deviceStatus = "on"
    }

    open fun turnOff() {
        deviceStatus = "off"
    }
}

class SmartTvDevice(deviceName: String, deviceCategory: String) :
    SmartDevice(name = deviceName, category = deviceCategory) {

    var speakerVolume = 2
        set(value) {
            if (value in 0..100) {
                field = value
            }
        }

     var channelNumber = 1
        set(value) {
            if (value in 0..200) {
                field = value
            }
        }

    fun increaseSpeakerVolume() {
        speakerVolume++
        println("Speaker volume increased to $speakerVolume.")
    }

    fun nextChannel() {
        channelNumber++
        println("Channel number increased to $channelNumber.")
    }

    override fun turnOn() {
        super.turnOn()
        println(
            "$name is turned on. Speaker volume is set to $speakerVolume and channel number is " +
                "set to $channelNumber."
        )
    }

    override fun turnOff() {
        super.turnOff()
        println("$name turned off")
    }
}

class SmartLightDevice(deviceName: String, deviceCategory: String) :
    SmartDevice(name = deviceName, category = deviceCategory) {

    var brightnessLevel = 0
        set(value) {
            if (value in 0..100) {
                field = value
            }
        }

    fun increaseBrightness() {
        brightnessLevel++
        println("Brightness increased to $brightnessLevel.")
    }

    override fun turnOn() {
        super.turnOn()
        brightnessLevel = 2
        println("$name turned on. The brightness level is $brightnessLevel.")
    }

    override fun turnOff() {
        super.turnOff()
        brightnessLevel = 0
        println("Smart Light turned off")
    }
}

open class SmartDevice(val name: String, val category: String) {

    var deviceStatus = "online"

    open val deviceType = "unknown"
    ...
}

class SmartTvDevice(deviceName: String, deviceCategory: String) :
    SmartDevice(name = deviceName, category = deviceCategory) {

    override val deviceType = "Smart TV"

    ...
}

class SmartLightDevice(deviceName: String, deviceCategory: String) :
    SmartDevice(name = deviceName, category = deviceCategory) {

    override val deviceType = "Smart Light"

    ...

}

open class SmartDevice(val name: String, val category: String) {

    ...

    private var deviceStatus = "online"

    ...
}

open class SmartDevice(val name: String, val category: String) {

    ...

    var deviceStatus = "online"
        protected set(value) {
           field = value
       }

    ...
}

open class SmartDevice(val name: String, val category: String) {

    ...

    var deviceStatus = "online"
        protected set

    ...
}

class SmartHome(
    val smartTvDevice: SmartTvDevice,
    val smartLightDevice: SmartLightDevice
) {

    var deviceTurnOnCount = 0
        private set

    ...
}

class SmartHome(
    val smartTvDevice: SmartTvDevice,
    val smartLightDevice: SmartLightDevice
) {

    var deviceTurnOnCount = 0
        private set

    fun turnOnTv() {
        deviceTurnOnCount++
        smartTvDevice.turnOn()
    }

    fun turnOffTv() {
        deviceTurnOnCount--
        smartTvDevice.turnOff()
    }

    ...

    fun turnOnLight() {
        deviceTurnOnCount++
        smartLightDevice.turnOn()
    }

    fun turnOffLight() {
        deviceTurnOnCount--
        smartLightDevice.turnOff()
    }

    ...

}

class SmartTvDevice(deviceName: String, deviceCategory: String) :
    SmartDevice(name = deviceName, category = deviceCategory) {

    ...

    protected fun nextChannel() {
        channelNumber++
        println("Channel number increased to $channelNumber.")
    }

    ...
}

open class SmartDevice protected constructor (val name: String, val category: String) {

    ...

}

internal open class SmartDevice(val name: String, val category: String) {

    ...

}

class SmartTvDevice(deviceName: String, deviceCategory: String) :
    SmartDevice(name = deviceName, category = deviceCategory) {

    private var speakerVolume = 2
        set(value) {
            if (value in 0..100) {
                field = value
            }
        }

    private var channelNumber = 1
        set(value) {
            if (value in 0..200) {
                field = value
            }
        }

    ...
}

class SmartLightDevice(deviceName: String, deviceCategory: String) :
    SmartDevice(name = deviceName, category = deviceCategory) {

    ...

    private var brightnessLevel = 0
        set(value) {
            if (value in 0..100) {
                field = value
            }
        }

    ...
}

class RangeRegulator() : ReadWriteProperty<Any?, Int> {

}

fun main() {
    ...
}

class RangeRegulator(
    initialValue: Int,
    private val minValue: Int,
    private val maxValue: Int
) : ReadWriteProperty<Any?, Int> {

}

class RangeRegulator(
    initialValue: Int,
    private val minValue: Int,
    private val maxValue: Int
) : ReadWriteProperty<Any?, Int> {

    override fun getValue(thisRef: Any?, property: KProperty<*>): Int {
    }

    override fun setValue(thisRef: Any?, property: KProperty<*>, value: Int) {
    }
}

import kotlin.properties.ReadWriteProperty
import kotlin.reflect.KProperty

open class SmartDevice(val name: String, val category: String) {
    ...
}

...

class RangeRegulator(
    initialValue: Int,
    private val minValue: Int,
    private val maxValue: Int
) : ReadWriteProperty<Any?, Int> {

    override fun getValue(thisRef: Any?, property: KProperty<*>): Int {
    }

    override fun setValue(thisRef: Any?, property: KProperty<*>, value: Int) {
    }
}

...

class RangeRegulator(
    initialValue: Int,
    private val minValue: Int,
    private val maxValue: Int
) : ReadWriteProperty<Any?, Int> {

    var fieldData = initialValue

    override fun getValue(thisRef: Any?, property: KProperty<*>): Int {
    }

    override fun setValue(thisRef: Any?, property: KProperty<*>, value: Int) {
    }
}

class RangeRegulator(
    initialValue: Int,
    private val minValue: Int,
    private val maxValue: Int
) : ReadWriteProperty<Any?, Int> {

    var fieldData = initialValue

    override fun getValue(thisRef: Any?, property: KProperty<*>): Int {
        return fieldData
    }

    override fun setValue(thisRef: Any?, property: KProperty<*>, value: Int) {
    }
}

class RangeRegulator(
    initialValue: Int,
    private val minValue: Int,
    private val maxValue: Int
) : ReadWriteProperty<Any?, Int> {

    var fieldData = initialValue

    override fun getValue(thisRef: Any?, property: KProperty<*>): Int {
        return fieldData
    }

    override fun setValue(thisRef: Any?, property: KProperty<*>, value: Int) {
        if (value in minValue..maxValue) {
            fieldData = value
        }
    }
}

class SmartTvDevice(deviceName: String, deviceCategory: String) :
    SmartDevice(name = deviceName, category = deviceCategory) {

    override val deviceType = "Smart TV"

    private var speakerVolume by RangeRegulator(initialValue = 2, minValue = 0, maxValue = 100)

    private var channelNumber by RangeRegulator(initialValue = 1, minValue = 0, maxValue = 200)

    ...

}

class SmartLightDevice(deviceName: String, deviceCategory: String) :
    SmartDevice(name = deviceName, category = deviceCategory) {

    override val deviceType = "Smart Light"

    private var brightnessLevel by RangeRegulator(initialValue = 0, minValue = 0, maxValue = 100)

    ...

}

import kotlin.properties.ReadWriteProperty
import kotlin.reflect.KProperty

open class SmartDevice(val name: String, val category: String) {

    var deviceStatus = "online"
        protected set

    open val deviceType = "unknown"

    open fun turnOn() {
        deviceStatus = "on"
    }

    open fun turnOff() {
        deviceStatus = "off"
    }
}

class SmartTvDevice(deviceName: String, deviceCategory: String) :
    SmartDevice(name = deviceName, category = deviceCategory) {

    override val deviceType = "Smart TV"

    private var speakerVolume by RangeRegulator(initialValue = 2, minValue = 0, maxValue = 100)

    private var channelNumber by RangeRegulator(initialValue = 1, minValue = 0, maxValue = 200)

    fun increaseSpeakerVolume() {
        speakerVolume++
        println("Speaker volume increased to $speakerVolume.")
    }

    fun nextChannel() {
        channelNumber++
        println("Channel number increased to $channelNumber.")
    }

    override fun turnOn() {
        super.turnOn()
        println(
            "$name is turned on. Speaker volume is set to $speakerVolume and channel number is " +
                "set to $channelNumber."
        )
    }

    override fun turnOff() {
        super.turnOff()
        println("$name turned off")
    }
}

class SmartLightDevice(deviceName: String, deviceCategory: String) :
    SmartDevice(name = deviceName, category = deviceCategory) {

    override val deviceType = "Smart Light"

    private var brightnessLevel by RangeRegulator(initialValue = 0, minValue = 0, maxValue = 100)

    fun increaseBrightness() {
        brightnessLevel++
        println("Brightness increased to $brightnessLevel.")
    }

    override fun turnOn() {
        super.turnOn()
        brightnessLevel = 2
        println("$name turned on. The brightness level is $brightnessLevel.")
    }

    override fun turnOff() {
        super.turnOff()
        brightnessLevel = 0
        println("Smart Light turned off")
    }
}

class SmartHome(
    val smartTvDevice: SmartTvDevice,
    val smartLightDevice: SmartLightDevice
) {

    var deviceTurnOnCount = 0
        private set

    fun turnOnTv() {
        deviceTurnOnCount++
        smartTvDevice.turnOn()
    }

    fun turnOffTv() {
        deviceTurnOnCount--
        smartTvDevice.turnOff()
    }

    fun increaseTvVolume() {
        smartTvDevice.increaseSpeakerVolume()
    }

    fun changeTvChannelToNext() {
        smartTvDevice.nextChannel()
    }

    fun turnOnLight() {
        deviceTurnOnCount++
        smartLightDevice.turnOn()
    }

    fun turnOffLight() {
        deviceTurnOnCount--
        smartLightDevice.turnOff()
    }

    fun increaseLightBrightness() {
        smartLightDevice.increaseBrightness()
    }

    fun turnOffAllDevices() {
        turnOffTv()
        turnOffLight()
    }
}

class RangeRegulator(
    initialValue: Int,
    private val minValue: Int,
    private val maxValue: Int
) : ReadWriteProperty<Any?, Int> {

    var fieldData = initialValue

    override fun getValue(thisRef: Any?, property: KProperty<*>): Int {
        return fieldData
    }

    override fun setValue(thisRef: Any?, property: KProperty<*>, value: Int) {
        if (value in minValue..maxValue) {
            fieldData = value
        }
    }
}

fun main() {
    var smartDevice: SmartDevice = SmartTvDevice("Android TV", "Entertainment")
    smartDevice.turnOn()

    smartDevice = SmartLightDevice("Google Light", "Utility")
    smartDevice.turnOn()
}

Android TV is turned on. Speaker volume is set to 2 and channel number is set to 1.
Google Light turned on. The brightness level is 2.