千锋20200228

千锋“逆战”学习第20天

      每日一句：调试完一个动态连接函数，固然值得兴奋，但真正的成功远还在无数个函数之后。
      今天学习了类的相关知识，内部类和Object类。
      下周继续加油。

作业

Question_09
2.有如下代码：

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

	public String toString() {
		return name + " " + age;
	}

}

public class TestStudent {
	public static void main(String[] args) {
		Student stu1 = new Student();
		Student stu2 = new Student("Tom", 18);
		System.out.println(stu1);
		System.out.println(stu2);
	}
}

运行结果：
null 0
Tom 18

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3.有如下代码：

public class TestEquals {
	public static void main(String[] args) {
		String str1 = new String("Hello");
		String str2 = new String("Hello");
		System.out.println(str1.equals(str2));
		System.out.println(str1==str2);
	}
}

运行结果：
true
false

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4.有如下代码：

class Animal {
}

class Dog extends Animal {
}

public class TestGetClass {
	public static void main(String[] args) {
		Animal a1 = new Dog();
		Animal a2 = new Animal();
		System.out.println(a1 instanceof Animal);
		System.out.println(a1.getClass() == a2.getClass());
	}
}

运行结果：
true
false

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5.java中的内部类包括：
      A.成员内部类
      B.静态内部类
      C.局部内部类
      D.匿名内部类
      E.公开内部类
      F.抽象内部类
      答案：A B C D

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6.为Worker类增加equals和toString方法

class Worker {
	String name;
	int age;
	double salary;

	public Worker(String name, int age, double salary) {
		super();
		this.name = name;
		this.age = age;
		this.salary = salary;
	}

	public boolean equals(Object obj) {
		if (this == obj) {
			return true;
		}
		if (obj == null) {
			return false;
		}
		if (this.getClass() != obj.getClass()) {
			return false;
		}
		Worker worker = (Worker) obj;
		if (this.name.equals(worker.name) && this.age == worker.age && this.salary == worker.salary) {
			return true;
		}
		return false;
	}

	public String toString() {
		return "Worker [name=" + name + ", age=" + age + ", salary=" + salary + "]";
	}
}

public class TestWorker {
	public static void main(String[] args) {
		Worker w1 = new Worker("tom", 30, 6000.0);
		Worker w2 = new Worker("jack", 31, 5000.0);
		Worker w3 = new Worker("tom", 30, 6000.0);

		System.out.println(w1);
		System.out.println(w2);
		System.out.println(w3);

		System.out.println(w1.equals(w2));
		System.out.println(w1.equals(w3));
	}
}

运行结果：
Worker [name=tom, age=30, salary=6000.0]
Worker [name=jack, age=31, salary=5000.0]
Worker [name=tom, age=30, salary=6000.0]
false
true

---------------------------------------------------------------------------------
9.有如下代码：

public class OuterClass {
	private int value1 = 100;
	private static int value2 = 200;
	public void method(int value3) {
		final int value4 = 400;
		class InnerClass{
			public void print(){
				/*1*/
			}
		}
	}
}

下列哪些代码放在/*1*/处编译通过
A.System.out.println(value1);
B.System.out.println(value2);
C.System.out.println(value3);
D.System.out.println(value4);

答：A B D

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10.代码填空

interface Light{
	void shine();
}
class Lamp{
	public void on(Light light) {
		light.shine();
	}
}
public class TestLamp {
	public static void main(String[] args) {
		Lamp lamp = new Lamp();
		//1.局部内部类
		
		//2.匿名内部类
		
	}
}

(1)在//1处使用局部内部类，调用lamp的on方法要求输出“shine in red”

class RedLight implements Light{
			public void shine() {
				System.out.println("shine in red");
			}
		}
		lamp.on(new RedLight());

(2)在//2处使用匿名内部类，调用lamp的on方法要求输出“shine in yellow”

lamp.on(new Light() {
			public void shine() {
				System.out.println("shine in yellow");
			}
		});

---------------------------------------------------------------------------------
Question_Difficult
8.根据类图，创建三个类，组成一个继承树，表示游戏中的角色

abstract class Role {// 所有职业的父类
	private String name;// 角色名字

	public abstract int attack();

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}
}

class Magicer extends Role {
	private int level;// 魔法等级（范围：1-10）

	public int attack() {// 返回法师对敌人攻击的伤害值
		return level * 5;
	}

	public int getLevel() {
		return level;
	}

	public void setLevel(int level) {
		if (level > 0 && level < 11) {
			this.level = level;
		} else {
			System.out.println("魔法等级已到上限");
		}
	}
}

class Solider extends Role {
	private int hurt;

	public int attack() {
		return hurt;
	}

	public int getHurt() {
		return hurt;
	}

	public void setHurt(int hurt) {
		this.hurt = hurt;
	}
}

class Team {
	static int i = 0;// 组队成员数
	static Role[] roles = new Role[6];

	public void addMember(Role role) {
		roles[i++] = role;
	}

	public int attackSum() {
		int sum = 0;
		for (int j = 0; j < i; j++) {
			sum += roles[j].attack();
		}
		return sum;
	}
}

public class TestGame {
	public static void main(String[] args) {
	Magicer m = new Magicer();
		m.setName("老爹");
		m.setLevel(8);
		System.out.println("魔法师：" + m.getName() + " 伤害值：" + m.attack());
		Solider s = new Solider();
		s.setName("成龙");
		s.setHurt(100);
		System.out.println("战士：" + s.getName() + " 伤害值：" + s.attack());
		Team t = new Team();
		t.addMember(m);
		t.addMember(s);
		System.out.println("小队总伤害：" + t.attackSum());
	}
}

运行结果：
魔法师：老爹 伤害值：40
战士：成龙 伤害值：100
小队总伤害：140

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10.在第八题基础上进行修改

//1.创建Role接口
interface Role {
	public int attack();

	public void practise();
}

//2.创建NamedRole类
abstract class NamedRole implements Role {
	private String name;
	private int age;

	public NamedRole() {
	}

	public NamedRole(String name, int age) {
		this.name = name;
		this.age = age;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public int getAge() {
		return age;
	}

	public void setAge(int age) {
		this.age = age;
	}
}

//3.创建MagicStick接口
interface MagicStick{
	public int fire();
}

//4.为MagicStick增加两个实现类
class GreenStick implements MagicStick{
	public int fire() {
		Date month = new Date();
		if(month.getMonth()>=6&&month.getMonth()<=8) {
			return 2;
		}
		else {
			return 1;
		}
	}
}
class BlackStrick implements MagicStick{
	public int fire() {
		Date month = new Date();
		if(month.getMonth()%2==0) {
			return 2;
		}
		else {
			return 1;
		}
	}
}

//5.修改Magicer类
class Magicer extends NamedRole {
	private int level;// 魔法等级（范围：1-10）
	MagicStick strick;
	public int attack() {// 返回法师对敌人攻击的伤害值
		return level * 5;
	}
	

	public Magicer(String name,int age, int level) {
		super(name,age);
		this.level = level;
	}


	public MagicStick getStrick() {
		return strick;
	}


	public void setStrick(MagicStick strick) {
		this.strick = strick;
	}


	public int getLevel() {
		return level;
	}

	public void setLevel(int level) {
		if (level > 0 && level < 11) {
			this.level = level;
		} else {
			System.out.println("模仿等级已到上限");
		}
	}
	public void practise() {
		level++;
		if(strick!=null) {
			level=level+1+strick.fire();
		}
	}
}

//6.增加Weapon接口
interface Weapon{
	void setSoldier(Soldier s);
	int fire();
}

//7.为Weapon增加两个实现类
public class Bolo implements Weapon{//大刀
	private Soldier s;
	public void setSoldier(Soldier s) {
		this.s = s;
	}
	public int fire() {
		if(s.getAge()>=18) {
			return 100;
		}else {
			return 50;
		}
	}
}
public class Pike implements Weapon{//矛
	private Soldier s;
	private String name;
	public Pike() {}
	public Pike(String name) {
		this.name = name;
	}
	public void setSoldier(Soldier s) {
		this.s = s;
	}
	public int fire() {
		if(s.getName().equals(name)) {
			return 1000;
		}else {
			return 25;
		}
	}
}

//8.修改Soldier类  
class Soldier extends NamedRole {
	private int hurt;
	private Weapon weapon;// 战士武器

	public Soldier(String name, int age, int hurt) {
		super(name, age);
		this.hurt = hurt;
	}

	public int getHurt() {
		return hurt;
	}

	public void setHurt(int hurt) {
		this.hurt = hurt;
	}

	public Weapon getWeapon() {
		return weapon;
	}

	public void setWeapon(Weapon weapon) {
		this.weapon = weapon;
	}

	public Soldier() {
	}

	public int attack() {
		int result = hurt;
		if (weapon != null) {
			result += weapon.fire();
		}
		return result;
	}

	public void practise() {
		hurt += 10;
	}
}

//9.测试
public class TestGame {
	public static void main(String[] args) {
		MagicStick ms1 = new GreenStick();
		MagicStick ms2 = new BlackStrick();
		Magicer m1 = new Magicer("老爹", 50, 10);
		Magicer m2 = new Magicer("特鲁", 26, 5);
		m1.setStrick(ms1);
		m2.setStrick(ms2);

		System.out.println(m1.getName() + "伤害值：" + m1.attack());
		System.out.println(m2.getName() + "伤害值：" + m2.attack());

		m1.practise();
		m2.practise();
		System.out.println("-----经过训练后-----");
		System.out.println(m1.getName() + "伤害值：" + m1.attack());
		System.out.println(m2.getName() + "伤害值：" + m2.attack());

		System.out.println("------------------");

		Weapon w1 = new Bolo();
		Weapon w2 = new Pike("成龙");
		Soldier s1 = new Soldier("小玉", 15, 200);
		Soldier s2 = new Soldier("成龙", 28, 150);

		s1.setWeapon(w1);
		w1.setSoldier(s1);

		s2.setWeapon(w2);
		w2.setSoldier(s2);

		System.out.println(s1.getName() + "伤害值：" + s1.attack());
		System.out.println(s2.getName() + "伤害值：" + s2.attack());

		s1.practise();
		s2.practise();
		System.out.println("-----经过训练后-----");
		System.out.println(s1.getName() + "伤害值：" + s1.attack());
		System.out.println(s2.getName() + "伤害值：" + s2.attack());
	}
}

运行结果：
老爹伤害值：50
特鲁伤害值：25
-----经过训练后-----
老爹伤害值：65
特鲁伤害值：40
------------------
小玉伤害值：250
成龙伤害值：1150
-----经过训练后-----
小玉伤害值：260
成龙伤害值：1160