练习8（图片题）

1. 

package cn.ch.w;

public class Person {
    private String name;
    private static int count;
    public Person()
    {
        count++;
        System.out.println("产生了"+count+"个小蘑菇。");
    }
    public String getInfo()
    {
        return "姓名:"+this.name;
    }
}

package cn.ch.w;

public class StaticDemo {
    public static void main(String args[])
    {
        new Person();
        new Person();
        new Person();
        new Person();
        new Person();
    }

}

 2.

package cn.ch.w;

public class Person {
    private String name;
    private static int count;
    public Person()
    {
        count++;
        this.name="xixixi-"+count;
    }
    public Person(String name)
    {
        this.name=name;
    }
    public String getInfo()
    {
        return"你谁？"+this.name;
    }

}

package cn.ch.w;

public class StaticDemo {
    public static void main(String args[])
    {
        System.out.println(new Person().getInfo());
        System.out.println(new Person("A").getInfo());
        System.out.println(new Person("B").getInfo());
        System.out.println(new Person().getInfo());
    }

}

3.

package cn.ch.w;

public class Single {
    private static Single instance=new Single();
    private Single()
    {
        
    }
    public static Single getInstance()
    {
        return instance;
    }
    public void print()
    {
        System.out.println("你喜欢吃蘑菇吗！！");
    }
}

package cn.ch.w;

public class SingleDemo {
    public static void main(String args[])
    {
        Single s=null;
        s = Single.getInstance();
        s.print();
    }

}

 4.

package cn.ch.w;

public class Person {
    private String name;
    private int age;
    static String city="捷克共和国";
    public Person(String name,int age)
    {
        this.name=name;
        this.age=age;
    }
    public String getInfo()
    {
        return "小蘑菇你叫啥？"+this.name+"，多大啦:"+this.age+",住在哪里啊"+city;
    }
}

package cn.ch.w;

public class StaticDemo {
    public static void main(String arges[])
    {
        Person per1=new Person("金针菇",21);
        Person per2=new Person("杏鲍菇",22);
        Person per3=new Person("茶树菇",23);
        System.out.println("------隐姓埋名前------");
        System.out.println(per1.getInfo());
        System.out.println(per2.getInfo());
        System.out.println(per3.getInfo());
        System.out.println("------隐姓埋名后------");
        Person.city="中华人名共和国";
        System.out.println(per1.getInfo()5.);
        System.out.println(per2.getInfo());
        System.out.println(per3.getInfo());
        
    }

}

5.

package cn.ch.w;

public class A {
    public A()
    {
        this.print();
    }
    public void print() {
    }

}
class B extends A{
    private int x=100;
    public B(int x){
        this.x=x;
    }
    public void printf()
    {
        System.out.println("x= "+x);
        
    }
}

package cn.ch.w;

public class TestJava {
    public static void main(String args[])
    {
        A a=new B(10);
    }
}