새싹교실/2014/자르반

public class Main {
	public static void main(String[] args) {
		TV tv1 = new TV();
		tv1.turnOn();
		tv1.setChannel(30);
		tv1.setVolume(3);

		TV tv2 = new TV(5, 10);
		tv2.turnOn();
		tv2.channelUp();
		tv2.channelUp();
		tv2.volumeUp();

		System.out.println("tv1's channel is " + tv1.getChannel()
				+ " and volume level is " + tv1.volumeLevel);
		System.out.println("tv2's channel is " + tv2.getChannel()
				+ " and volume level is " + tv2.volumeLevel);
	}
}

class TV {
	private int channel; // Default channel is 1
	int volumeLevel; // Default volume level is 1
	boolean on; // By default TV is off

	public TV() {
		channel = 5;
		volumeLevel = 3;
		on = false;
	}

	public TV(int newChannel, int newVolume) {
		channel = newChannel;
		volumeLevel = newVolume;
	}

	public void turnOn() {
		on = true;
	}

	public void turnOff() {
		on = false;
	}

	public void setChannel(int newChannel) {
		if (on && newChannel >= 1 && newChannel <= 120)
			channel = newChannel;
	}

	public void setVolume(int newVolumeLevel) {
		if (on && newVolumeLevel >= 1 && newVolumeLevel <= 7)
			volumeLevel = newVolumeLevel;
	}

	public void channelUp() {
		if (on && channel < 120)
			channel++;
	}

	public void channelDown() {
		if (on && channel > 1)
			channel--;
	}

	public void volumeUp() {
		if (on && volumeLevel < 7)
			volumeLevel++;
	}

	public void volumeDown() {
		if (on && volumeLevel > 1)
			volumeLevel--;
	}

	public int getChannel() {
		return channel;
	}
}