11.6调用圆面积、周长的有参无参函数，修改圆的半径，TV,sameperson;

1.

package cn.dede.w;
//圆的面积、周长的类
public class CircleA
{
    private double radius;//私有化半径
    
    public CircleA(double radius) //建立有参函数
    {
        this.radius = radius;//键盘输入了一个值，赋值给了半径
    }
     public CircleA() 
     {
        this.radius = 1;//无参函数，自动赋值为1
     }

        
     public double getArea()
     {
            return radius * radius * Math.PI;//获取圆面积的返回值

     }

       
     public double getPerimeter() 
     {
            return 2 * Math.PI * radius;//获取圆周长的返回值
     }
     public void setRadius(double newRadius) 
     {
            this.radius=newRadius;//更改第一次的圆半径
     }
}

package cn.dede.w;

public class CirclePlay 
{
    public static void main(String[] args) {
        CircleA circle1=new CircleA();//建的第一个圆
        double area=circle1.getArea();//调用无参函数，并赋值给area
        System.out.println(area);//输出第一个圆
        System.out.println(circle1.getPerimeter());//输出第一个圆周长
        CircleA circle2=new CircleA(10);//建的第二个圆，调用有参函数，半径为10
        System.out.println(circle2.getArea()); //输出第一个圆面积
        System.out.println(circle2.getPerimeter());//输出第二个圆周长
        double ridius=10;//给半径赋一个值
        double areaCircle=Math.PI*ridius*ridius;//算面积
        System.out.println(areaCircle);
        circle2.setRadius(5);//调用修改半径的类，将半径修改成5
        System.out.println(circle2.getArea());
    }
}

 2.

package cn.dede.w;
//把上边的两个圆的类合并成一个类，并实现同样功能
public class CirclePlayB 
{
     private double radius;
        public CirclePlayB()
        {
            this.radius=1;//给半径赋值
        }
        public CirclePlayB(double radius)
        {
            this.radius=radius;
        }
        public double getArea() 
        {
            return Math.PI*radius*radius;
        }
        public double getPerimeter()
        {
            return 2*Math.PI*radius;
        }
        
        public static void main(String[] args)
        {
            CirclePlayB cir1=new CirclePlayB();
            System.out.println("半径是 "+cir1.radius+" 面积是： "+cir1.getArea());
            CirclePlayB cir2=new CirclePlayB(10);
            System.out.println("半径是 "+cir2.radius+" 面积是 "+cir2.getArea());
        }
}

3.

package cn.dede.w;

public class TVA 
{
         public int channel=1;
        public int volumeLevel=1;//调音量
        public boolean on=false;
        
        public TVA() {
            
        }
        public void turnOn() {
            on =true;
            System.out.println("dengdengdeng~deng，已开机");
        }
        public void turnOff() {
            on=false;
            System.out.println("biu~。");
        }
        public int getChannel() {
            return channel;
        }
        public void setChannel(int channel) {
            if(on) 
            {
                System.out.println("欢迎收看电影频道，可调频。");
                if(channel>=1&&channel<=120) 
                {
                    this.channel = channel;
                    System.out.println("频道已调到 "+channel+" 台");
                }
                else 
                {
                    System.out.println("搜索不到信号。");
                }
            }
            else 
            {
                System.out.println("-.-没电啊");
            }
        }
        public int getVolumeLevel() {
            return volumeLevel;
        }
        public void setVolumeLevel(int volumeLevel) {
            if(on) {
                System.out.println("调节音量");
                if(volumeLevel>=1&&volumeLevel<=7) {
                    this.volumeLevel = volumeLevel;
                    System.out.println("音量已调节到 "+volumeLevel+" .");
                }
            }else {
                System.out.println("-.-没电啊");
            }
            
        }
        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--;
            }
        }
        
}

package cn.dede.w;

public class TVPlay 
{
      public static void main(String[] args) {
        
        TVA tv2=new TVA();
        tv2.turnOn();
        System.out.println("频道是： "+tv2.channel+"；音量是 "+tv2.volumeLevel);
        tv2.channelUp();
        System.out.println("频道是： "+tv2.channel+"；音量是  "+tv2.volumeLevel);
        tv2.channelUp();
        System.out.println("频道是： "+tv2.channel+" ；音量是 "+tv2.volumeLevel);
        tv2.channelUp();
        System.out.println("频道是： "+tv2.channel+" ；音量是 "+tv2.volumeLevel);
        tv2.volumeUp();
        System.out.println("频道是： "+tv2.channel+" ；音量是 "+tv2.volumeLevel);
        tv2.volumeUp();
        System.out.println("频道是： "+tv2.channel+" ；音量是 "+tv2.volumeLevel);
        tv2.volumeUp();
        System.out.println("频道是： "+tv2.channel+" ；音量是 "+tv2.volumeLevel);
        
        
    }

}

 4.

package cn.dede.w;

public class HelloworldA 
{
    public static void main(String args[])
    {
        new HelloworldA().fun();
    }
    public void fun()
    {
        System.out.println("你好！世界2！");
    }
}

5.

package cn.dede.w;
class SamePerson
{
    private String name;
    private int age;
    public SamePerson(String name, int age)
    {
        this.name=name;
        this.age=age;
    }

public boolean compare(SamePerson per)
{
    if(this.name.equals(per.name)&&this.age==per.age)
    {
        return true;
    }
        else
    {
        return false;
    }
}
public String getName()
{
    return this.name;
}
public int getAge()
{
    return this.age;
}


}

package cn.dede.w;

public class SamePersonDemoA
{
    public static void main(String args[])
    {
        SamePerson per1=new SamePerson("李白",30);
        SamePerson per2=new SamePerson("李白",30);
        if(per1.compare(per1))
        {
        System.out.println("是同一个人！");    
        }
        }
    }

 6.

package cn.dede.w;
public class SamePersonB
{
    private String name;
    private int age;
    public SamePersonB (String name,int age )
{
    this.name=name;
    this.age=age;
}
public boolean compare(SamePersonB per)
{
    if(this==per)
        {
                return true;
        }
    else
    {
        return false;
    }
}
public String getName()
{
return this.name;
}
public int getAge()
{
    return this.age;
}

}

package cn.dede.w;

public class SamePersonDemoB {
    
        public static void main(String args[])
        {
            SamePersonB per1=new SamePersonB("李黑",30);
            SamePersonB per2=new SamePersonB("李黑",30);
            if(per1.compare(per1))
            {
                System.out.println("是同一个人");
            }
            
        }
    
}

 7.

package cn.dede.w;

class SamePersonC
{
    private String name;
    private int age;
    public SamePersonC(String name, int age)
    {
        this.name=name;
        this.age=age;
    }

public void fun(SamePersonC per)
{
    per.name="李蓝";
    per.age=33;
}
public String getName()
{
    return this.name;
}
public int getAge()
{
    return this.age;
}


}

package cn.dede.w;

public class SamePersonDemoC
{
public static void main(String args[])
{
    SamePersonC per =new SamePersonC("李黑",30);
    per.fun(per);
    System.out.println(per.getName()+ "-->" +per.getAge());
}
}

 8.

package cn.dede.w;

class SamePersonD
{
    private String name;
    private int age;
    public SamePersonD(String name, int age)
    {
        this.name=name;
        this.age=age;
    }

public String getName()
{
    return this.name;
}
public int getAge()
{
    return this.age;
}


}

package cn.dede.w;

public class SamePersonDemoD 
{
public static void main(String args[])
{
    SamePersonD per1 =new SamePersonD("李黑",30);
    SamePersonD per2 =new SamePersonD("李黑",30);
    if(per1.getName().equals(per2.getName())&&per1.getAge()==per2.getAge())
    {
        System.out.println("是同一个人");
    }
}
}