//写出程序运行结果
class Eye {// 猫的眼睛类
private String color;
public Eye(String color) {
this.color = color;
}
}
class Cat {// 猫类
private String name;
private Eye eye;
public Cat(String name, Eye eye) {
this.name = name;
this.eye = eye;
}
public boolean equals(Object obj) {
Cat cat = (Cat) obj;
if (this.name.equals(cat.name) && this.eye == cat.eye)
return true;
return false;
}
}
public class CatDemo {
public static void main(String[] args) {
Eye e1=new Eye("蓝色");
Cat tom1=new Cat("Tom",e1);
Cat tom2=new Cat("Tom",e1);
System.out.println(tom1==tom2);
System.out.println(tom1.equals(tom2));
}
}
false --- true
举一反三
- 给出下列【代码】注释标注的代码的输出结果。class Tom {int weight = 10;void Tom(){weight = 18;}}public class E {public static void main(String args[]) {Tom cat = new Tom();System.out.println(cat.weight); //【代码】}}
- 请阅读下面的程序,写出运行结果,如果编译失败,写明失败原因。 abstract class Animal{ public final abstract void eat(); } class Cat extends Animal{ public void eat(){ System.out.println("cat...fish"); } } class CatDemo{ public static void main(String[] args){ Animal a = new Cat(); a.eat(); } }
- 下列程序的运行结果是（ ）class Demo{private String name;Demo(String name){this.name = name;}private static void show(){System.out.println(name)}public static void main(String[] args){Demo d = new Demo(“lisa”);d.show();}}
- 有如下类的定义，创建Employee对象正确的是（） public class Employee{ private int age; private String name; public void Employee(){ } public Employee(int age){ this.age = age; } public Employee(String name){ this.name = name; } } A: Employee e = new Employee( ) B: Employee e = new Employee(10); C: Employee e = new Employee(tom); D: Employee e = new Employee(10,"tom");
- （6-3）阅读程序，写出程序运行结果。 class Book{ private static int counter=0; private int id=1; private String name; public Book(String name) { this.name = name; counter++; this.id=this.id+8; } public static int getCounter() { return counter; } public int getID() { return this.id; } } public class BookDemo{ public static void main(String[] args) { Book b1=new Book("红楼梦"); Book b2=new Book("西游记"); Book b3=new Book("儒林外史"); System.out.println(b3.getCounter()*Book.getCounter()*b3.getID()); } }
内容
- 0
（6-9）请阅读程序，写出程序运行结果。 class Phone{ private String name; private int price; public Phone(String name, int price) { this.name = name; this.price = price; } public String toString() { return ""+this.price; } } public class PhoneDemo { public static void main(String[] args) { StringBuffer sb=new StringBuffer(); Phone [] list=new Phone[3]; list[0]=new Phone("华为",3000); list[1]=new Phone("小米8",4000); list[2]=new Phone("vivo R10",2300); for(Phone p:list) sb.append(p); System.out.println(sb.toString()); } }
- 1
（7-12）请阅读程序，写出程序运行结果。 class A{ static String name="tom"; static int getX() { return 2; } int getY() { return 3; } } class B extends A{ static String name="Tuny"; static int getX() { return 4; } int getY() { return 5; } } class C extends A{ static String name="Tuny"; static int getX() { return 4; } int getY() { return 5; } } interface D{ int getY(); } class E implements D{ public int getY() { return 6; } } public class Demo{ public static void main(String[] args) { A a=new A(); A b=new B(); A c=new C(); D d=new E(); int sum=a.name.length()+b.getX()+c.getY()+d.getY(); System.out.println(sum); } }
- 2
有如下类的定义，创建Employee对象错误的是（） public class Employee{ private int age; private String name; public Employee(int age){ this.age = age; } public Employee(String name){ this.name = name; } public Employee(int age,String name){ this(age); this.name = name; } } A: Employee emp = new Employee(10); B: Employee emp = new Employee("Tom"); C: Employee emp = new Employee(); D: Employee emp = new Employee(10,"Tom");
- 3
【填空题】public class ThisTest{ private String name; private int age; public ThisTest() { System.out.println("产生一个新的Person对象。"); } public ThisTest (String name, int age) { this(); this.name = name; this.age = age; } public String getInf() { return "姓名:" + name + ",年龄:" + age; } public static void main(String[] args) { ThisTest per = new ThisTest("张三", 20); System.out.println(per.getInf()); } } 运行结果为:____
- 4
class Person { String name; int age; [br][/br] public Person(String name, int age) { super(); this.name = name; this.age = age; } @Override public boolean equals(Object obj) { Person person=null; if(obj instanceof Person) person=(Person)obj; if(name.equals(person.name)&&age==person.age) return true; return false; } } class Test{ public static void main(String[] args) { Person person1 = new Person("张三", 12); Person person2 = new Person("张三", 12); System.out.println(person1.equals(person2));//运行结果是？ } } 程序运行结果是什么？ A: true B: false