第二题

public class Tv { private int channel: private boolean on; private int volumeLevel; public TV(int channel, boolean on, int volumeLevel){ super(); this.channel = channel; this.on=on; this.volumeLevel = volumeLevel; public Tv() this.channel=1; this.on=false; this.volumeLevel=1; I public void turn0n(){ //打开电视 on=true;} public void turn0ff(){ //关闭电视 on=false; public void channelup(){ /1微道数加一 channel++; } public void channerlDown(){ //损道微派一 channel--j