阅读程序，给出结果： abstract class Shape { //定义抽象类Shape和抽象方法display abstrac

1.abstract class Shape { //定义抽象类Shape和抽象方法display abstract void display(); } class Circle extends Shape { void display() { //实现抽象类的方法 System.out.println(Circle); } } class Rectangle extends Shape { void display() { //实现抽象类的方法 System.out.println(Rectangle); } } class Triangle extends Shape { void display() { //实现抽象类的方法 System.out.println(Triangle); } } public class AbstractClassDemo{ public static void main(String args]){ (new Circle()).display(); //定义无名对象来调用对应的display方法 (new Rectangle()).display(); (new Triangle()).display(); }

2.阅读程序，给出结果： // AbstractClassDemo.java源代码如下： Abstract class Shape { //定义抽象类Shape和抽象方法display abstract void display(.); } Class Circle extends Shape { void display(.) { //实现抽象类的方法 System.out.println("Circle"); } } Class Rectangle extends Shape { void display(.) { //实现抽象类的方法 System.out.println("Rectangle"); } } Class Triangle extends Shape { void display(.) { //实现抽象类的方法 System.out.println("Triangle"); } } Public class AbstractClassDemo{ public static void main(String args]){ (new Circle(.)).display(.); //定义无名对象来调用对应的display方法 (new Rectangle(.)).display(.); (new Triangle(.)).display(.); } } 输出结果是 ?

3.阅读程序，给出结果：// AbstractClassDemo.java源代码如下：abstract class Shape { //定义抽象类Shape和抽象方法display abstract void display();}class Circle extends Shape { void display() { //实现抽象类的方法 System.out.println("Circle"); }}class Rectangle extends Shape { void display() { //实现抽象类的方法 System.out.println("Rectangle"); }}class Triangle extends Shape { void display() { //实现抽象类的方法 System.out.println("Triangle"); }} public class AbstractClassDemo{ public static void main(String args[]){ (new Circle()).display(); //定义无名对象来调用对应的display方法 (new Rectangle()).display(); (new Triangle()).display(); }}输出结果是：（1）（2）（3）

4.25.3、以下程序输出的结果为：abstract class Shape { //定义抽象类Shape和抽象方法displayabstract void display();}class Circle extends Shape {void display() {//实现抽象类的方法System.out.println("Circle");}}class Rectangle extends Shape {void display() { //实现抽象类的方法System.out.println("Rectangle");}}class Triangle extends Shape {void display() { //实现抽象类的方法System.out.println("Triangle");}}public class AbstractClassDemo{public static void main(String args]){(new Circle()).display();//定义无名对象来调用对应的display方法(new Rectangle()).display();(new Triangle()).display();}}

5. 阅读程序,给出结果:// AbstractClassDemo。java源代码如下:abstract class Shape { //定义抽象类Shape和抽象方法displayabstract void display();}class Circle extends Shape {void display() { //实现抽象类的方法System.out。println("Circle");}}class Rectangle extends Shape {void display() { //实现抽象类的方法System。out.println("Rectangle”);}}class Triangle extends Shape {void display() { //实现抽象类的方法System.out.println("Triangle”);}}public class AbstractClassDemo{public static void main(String args[]){(new Circle())。display(); //定义无名对象来调用对应的display方法(new Rectangle())。display();(new Triangle())。display();}}输出结果是 ?

6.以下程序的输出结果为。 abstract class Shape { abstract void display(); } class Circle extends Shape { void display() { System.out.println("Circle"); } } class Rectangle extends Shape { void display() { System.out.println("Rectangle"); } } class Triangle extends Shape { void display() { System.out.println("Triangle"); } } public class AbstractClassDemo{ public static void main(String args[]){ (new Circle()).display(); (new Rectangle()).display(); (new Triangle()).display(); } }

}

class Rectangle extends Shape {

void display() { //实现抽象类的方法

System.out.println("Rectangle");

}

class Triangle extends Shape {

void display() { //实现抽象类的方法

System.out.println("Triangle");

}

public class AbstractClassDemo{

public static void main(String args]){

(new Circle()).display();//定义无名对象来调用对应的display方法

(new Rectangle()).display();

(new Triangle()).display();

}

输出结果是 ?

">7.阅读程序，给出结果：

// AbstractClassDemo.java源代码如下：

abstract class Shape { //定义抽象类Shape和抽象方法display

abstract void display();

}

class Circle extends Shape {

void display() {//实现抽象类的方法

System.out.println("Circle");

}

class Rectangle extends Shape {

void display() { //实现抽象类的方法

System.out.println("Rectangle");

}

class Triangle extends Shape {

void display() { //实现抽象类的方法

System.out.println("Triangle");

}

public class AbstractClassDemo{

public static void main(String args]){

(new Circle()).display();//定义无名对象来调用对应的display方法

(new Rectangle()).display();

(new Triangle()).display();

}

输出结果是 ?

}

class Rectangle extends Shape {

void display() { //实现抽象类的方法

System.out.println("Rectangle");

}

class Triangle extends Shape {

void display() { //实现抽象类的方法

System.out.println("Triangle");

}

public class AbstractClassDemo{

public static void main(String args]){

(new Circle()).display();//定义无名对象来调用对应的display方法

(new Rectangle()).display();

(new Triangle()).display();

}

">8.3、以下程序输出的结果为：

abstract class Shape { //定义抽象类Shape和抽象方法display

abstract void display();

}

class Circle extends Shape {

void display() {//实现抽象类的方法

System.out.println("Circle");

}

class Rectangle extends Shape {

void display() { //实现抽象类的方法

System.out.println("Rectangle");

}

class Triangle extends Shape {

void display() { //实现抽象类的方法

System.out.println("Triangle");

}

public class AbstractClassDemo{

public static void main(String args]){

(new Circle()).display();//定义无名对象来调用对应的display方法

(new Rectangle()).display();

(new Triangle()).display();

}

9.public abstract class Shape { private int x； private int y； public abstract void draw（）； public void setAnchor（int x， int y） { this.x = x； this.y = y； } } Which two classes use the Shape class correctly？（）选项： A、 public class Circle implements Shape { private int radius； } B、 public abstract class Circle extends Shape { private int radius； } C、 public class Circle extends Shape { private int radius； public void draw（）； } D、 public abstract class Circle implements Shape { private int radius； public void draw（）； } E、 public class Circle extends Shape { private int radius；public void draw（） {/* code here */} } F、 public abstract class Circle implements Shape { private int radius；public void draw（） { / code here */ } }

10.Given:Public abstract class Shape {Private int x;Private int y;Public abstract void draw();Public void setAnchor(int x,int y){This.x=x;This.y=y;}}Which two classes use the shape class correctly? 选项： A:public class Circle implements Shape{Private int radius;} B:public abstract class Circle implements Shape{Private int radius;} C:public class Circle extends Shape{Private int radius;Public void draw();} D:public abstract class Circle implements Shape{Private int radius;Public void draw();} E:public class Circle extends Shape{Private int radius;Public void draw();{/*code here*/}} F:public abstract class Circle implements Shape{Private int radius;Public void draw();{/*code here*/}}

11.Given:Public abstract class Shape {Private int x;Private int y;Public abstract void draw();Public void setAnchor(int x,int y){This.x=x;This.y=y;}}Which two classes use the shape class correctly? 选项： A:public class Circle implements Shape{ private int radius; } B:public abstract class Circle implements Shape{ private int radius; } C:public class Circle extends Shape{ private int radius; public void draw(); } D:public abstract class Circle implements Shape{ private int radius; public void draw(); } E:public class Circle extends Shape{ private int radius; public void draw();{/*code here*/} } F:public abstract class Circle implements Shape{ private int radius; public void draw();{/*code here*/} }

12.给定如下程序: public abstract class Shape { private int x; private int y; public abstract void draw(); public void setAnchor(int x, int y) { this.x = x; this.y = y; } } 下列哪个选项是正确的?(). A: public class Circle implements Shape {private int radius; } B: public abstract class Circle extends Shape { private int radius; } C: public class Circle extends Shape { private int radius; public void draw(); } D: public abstract class Circle implements Shape { private int radius; public void draw(); }

13.public abstract class Shape { private int x; private int y; public abstract void draw(); public void setAnchor(int x, int y) { this.x = x; this.y = y; } } 下列哪一个类是对Shape的正确引用（）。选项： A、public class Circle implements Shape { private int radius; } B、public abstract class Circle extends Shape { private int radius; } C、public class Circle extends Shape { private int radius; public void draw(); } D、public abstract class Circle implements Shape { private int radius; public void draw(); }

14.1、补全下面教师类的display()方法，显示下面结果：。 Name=zhangSalary=4580.0Table=Rect public class Test{ public static void main(String[] args) { TableInfo t=new TableInfo("Rect", 4, 100,3600); Teacher zhang=new Teacher("zhang", 40, 4580, "VP", t); zhang.display(); }}class Teacher{ private String name; private int age; private double salary; private String professionalTitle; private TableInfo table; public Teacher(String name,int age,double salary,String professionalTitle,TableInfo table){ this.name = name; this.age = age; this.salary =salary; this.professionalTitle = professionalTitle; this.table = table; } public void display(){ System.out.println("Name=" + name); System.out.println("Salary=" + salary); }}class TableInfo{ private String shape; private int legs; private int hight; private double area; public TableInfo(String shape, int legs,int hight,double area){ this.shape = shape; this.legs = legs; this.hight = hight; this.area = area; } public void print(){ System.out.println("Table=" + shape); }}选项： A:table.print(); B:System.out.println(“Table=”+ table); C:System.out.println(“Table=”+ shape); D:其他

15.abstract class SuperAbstract{ void a(　　){…} abstract void b(　　); abstract int c(int i); } interface AsSuper { void x(　　); } abstract class SubAbstract extends SuperAbstract implements AsSuper { public void b(　　){…} abstract String f(　　); } public class InheritAbstract extends SubAbstract{ public void x(　　){…} public int c(int i ) {…} public String f(　　){…} public static void main(String args]){ InheritAbstract instance=new InheritAbstract(　　); instance.x(　　); instance.a(　　); instance.b(　　); instance.c(　　); System.out.println(　　)); } } 在以上这段程序中：抽象类有：SuperAbstract和 (　　) (　　) 非抽象类有： (　　) (　　) 接口有： (　　) (　　) AsSuper中的x(　　)方法是(　　)方法，所以在InheritAbstract中必须对它进行(　　) (　　) SubAbstract； (　　) InheritAbstract； (　　) AsSuper； (　　) 抽象； (　　) 覆盖和实现。

16.interface Sport{ void play();}class Display{ public void show(){ System.out.println("运动器材信息："); } }class Ball extends Display Sport{ String color; double price; public Ball(String color,double price) { this.color=color; this.setPrice(price); } public double getPrice() { return price; } public void setPrice(double price) { if(price<0){ this.price = price; }else System.out.println("错误！"); }@Override public void play() { System.out.println("用脚踢着玩！"); }

17.请完成如下程序class Shape { protected int width, height; public Shape( int a=0, int b=0) { width = a; height = ______ ; } public ______ int area() { Console.WriteLine("父类的面积："); ______ 0; }class Rectangle: Shape{ public Rectangle( int a=0, int b=0): base(a, b) { } public override int area () { Console.WriteLine("Rectangle 类的面积："); return (width * height); } } class Triangle: Shape{ public Triangle(int a = 0, int b = 0): ______ (a, b) { } public ______ ______ area() { Console.WriteLine("Triangle 类的面积："); return (width * height / 2); } }class Caller { public void CallArea( ______ sh) { int a; a = sh.area(); Console.WriteLine("面积： {0}", a); } } class Tester{ static void Main(string[] args) { Caller c = new Caller(); Rectangle r = new Rectangle(10, 7); Triangle t = new Triangle(10, 5); c.CallArea(r); c.CallArea(t); Console.ReadKey(); } } }Rectangle 类的面积：面积： 70 Triangle 类的面积：面积： 25

18.import static java.lang.System.out;public class ShapeDemo{ public static void main(String[] args){ Shape shape=new Circle(5); out.println(shape.area()); }} Shape{ double area();}class Circle implements Shape{ private double r; public Circle(double _r){ this.r=_r; } @Override public double area(){ return Math.PI*r*r; }}

19.public abstract class Animal { public abstract void eat();}public class Cat extends Animal{ public void 【代码1】(){ System.out.println("猫吃猫粮"); }}public class Test { public static void main(String[] args) { Animal a = new 【代码2】(); a.eat(); }}

20.阅读源代码，写程序运行结果：public interface Shape { public double area();}public class Rectangle implements Shape{ private double width; private double height; public Rectangle(double w, double h) { width = w; height = h;} public Rectangle(double w) { width = w; height = w;} public Rectangle() { width = 1; height = 1; } @Override public double area() { return width*height; }}public class Circle implements Shape { private double radius; private static final double PI = 3.14; public Circle(double r) { radius = r;} public Circle() { radius = 1; } @Override public double area() { return radius*radius*PI; }} public class ShapeTest{ public static void main(String[] args) { Shape[] shapes = new Shape[5]; shapes[0] = new Rectangle(1,2); shapes[1] = new Rectangle(3); shapes[2] = new Rectangle(); shapes[3] = new Circle(2); shapes[4] = new Circle(); for(int i=0;i

21.以下程序的运行结果是（） class Base { protected String var = "父类变量"; public static void staticMethod() { System.out.println("父类静态方法"); } } class Sub extends Base { public String var="子类变量"; public static void staticMethod() { System.out.println("子类静态方法"); } } public class Test { public static void main(String[] args) { System.out.println(new Sub().var); Base b = new Sub(); b. staticMethod() } }

22.#include #include int count=0; class Point {int x,y; public: Point( ) { x=1; y=1; count++; } ~Point( ){ count--; } friend void display( ); }; void display( ) { cout <<"There are "<

23.按要求填空 Abstract class SuperAbstract{ void a(.){…} abstract void b(.); abstract int c(int i); } Interface AsSuper { void x(.); } Abstract class SubAbstract extends SuperAbstract implements AsSuper { Public void b(.){…} abstract String f(.); } Public class InheritAbstract extends SubAbstract{ public void x(.){…} public int c(int i ) {…} public String f(.){…} public static void main(String args]){ InheritAbstract instance=new InheritAbstract(.); instance.x(.); instance.a(.); instance.b(.); instance.c(100); System.out.println(instance.f(.)); } } 在以上这段程序中：抽象类有：SuperAbstract和　（1）　　(写出类名) 非抽象类有：　　　　　　　（2）　　(写出类名) 接口有：　　　　　　　　　（3）　　(写出接口名) AsSuper中的x(.)方法是（4）方法，所以在InheritAbstract中必须对它进行（5）

24.按要求填空Abstract class SuperAbstract{ void a(){…} abstract void b(); abstract int c(int i);}Interface AsSuper{ void x();}Abstract class SubAbstract extends SuperAbstract implements AsSuper{Public void b(){…} abstract String f();}Public class InheritAbstract extends SubAbstract{ public void x(){…} public int c(int i ) {…} public String f(){…} public static void main(String args]){ InheritAbstract instance=new InheritAbstract(); instance.x(); instance.a(); instance.b(); instance.c(100); System.out.println(instance.f()); }}在以上这段程序中：抽象类有：SuperAbstract和 (1) (写出类名)非抽象类有： (2) (写出类名)接口有： (3) (写出类名)AsSuper中的x()方法是(4)方法，所以在InheritAbstract中必须对它进行(5)

25.关于下述代码,说法正确的是?package shapes;abstract class Triangle {abstract String getDescription();}class RightTriangle extends Triangle {protected String getDescription() { return "rt"; } // g1}public abstract class IsoscelesRightTriangle extends RightTriangle { // g2public String getDescription() { return "irt"; }public static void main(String[] edges) {final Triangle shape = new IsoscelesRightTriangle(); // g3System.out.print(shape.getDescription());}} 选项：A、无法编译因为 g1行 B、无法编译因为 g2行 C、无法编译因为 g3行 D、代码可编译且运行无问题