下面程序运行的结果是：第一行，第二行。 class CCircle { protected double radius; public

1.(填空题,1.0分) 下面程序运行的结果是：第一行（），第二行（） class CCircle { protected double radius; public CCircle(double r) { radius=r; } public void show() { System.out.println("Radius="+radius); } } public class CCoin extends CCircle { private int value; public CCoin(double r, int v) { super(r); value=v; } public void show() { System.out.println("Radius="+radius+" Value="+value); } public static void main(String] args) { CCircle circle=new CCircle(2.0); CCoin coin=new CCoin(3.0,5); circle.show(); coin.show(); } }

2.Public class Cirle { double radius; public double area; public Cirle(double r) {radius = r;} public double getRadius() {return radius;} public void setRadius(double r) {radius = r;} public double getArea() { return /*???*/; }}Class App { public static void main(String] args) { Cirle c1 = new Cirle(17.4); c1.area = Math.PI*c1.getRadius()*c1.getRadius(); }}The class is poorly encapsulated. You need to change the circle class to compute and return the area insteadWhich two modifications are necessary to ensure that the class is being properly encapsulated? 选项： A::remove the Area field B:: Change the getArea( ) method as follows: public double getArea ( ) { return Match.PI * radius * radius; } C:: Add the following method: public double getArea ( ) {area = Match.PI * radius * radius; } //没有return D:: Change the cacess modifier of the |setRadius ( )| method to be protected.

3.Public class Cirle {Double radius;Public double area;Public Cirle(double r) {radius = r;}Public double getRadius() {return radius;}Public void setRadius(double r) {radius = r;}Public double getArea() { return /*???*/; }}Class App {Public static void main(String] args) {Cirle c1 = new Cirle(17.4);C1.area = Math.PI*c1.getRadius()*c1.getRadius();}}The class is poorly encapsulated. You need to change the circle class to compute and return the area insteadWhich two modifications are necessary to ensure that the class is being properly encapsulated? 选项： A::remove the Area field B:: Change the getArea( ) method as follows: public double getArea ( ) { return Match.PI * radius * radius; } C:: Add the following method: public double getArea ( ) {area = Match.PI * radius * radius; } //没有return D:: Change the cacess modifier of the |setRadius ( )| method to be protected.

4.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 */ } }

5.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*/} }

6.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(); }

7.程序阅读题：class Point{ int x, y; Point(int x, int y){ this.x=x; this.y=y; System.out.println("父类构造方法被调用！"); }} class Circle extends Point{ int radius; Circle(int r, int x, int y){ super(x, y); this.radius=r; System.out.println("子类构造方法被调用！"); }}public class testInherence { public static void main(String args[ ]) { Circle c1=new Circle(1,1,1); }}运行结果：

8.public class ThisTester { static int value = 2020; public static void main(String[] args) throws Exception{ new ThisTester().printValue(); } private void printValue(){ int value = 20; System.out.println(this.value); } } 代码运行的结果是_________。

10."Given:1. public abstract class Shape {2. private int x;3. private int y;4. public abstract void draw();5. public void setAnchor(int x, int y) {6. this.x = x;7. this.y = y;8. }9. }Which class 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(); }

11.Given: 1. public abstract class Shape { 2. private int x; 3. private int y; 4. public abstract void draw(); 5. public void setAnchor(int x, int y) { 6. this.x = x; 7. this.y = y; 8. } 9. } Which class 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(); }

12.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; }}

13.补充完整下面的类定义： const double PI=3.14； class Circle //圆形物体的抽象基类 protected： double r； //半径 public： Circle(double radius=0)：r(radius) (13) ； //计算圆形物体表面积的纯虚函数声明； class Cylinder：public Circle //圆柱体类 double h； //高度 public： Cylinder(double radius=0，double height=0)； Circle(radius)，h(height) Virtual double Area( )return 2*PI*r*(r+h)； //计算圆柱体的表面积；

14.补充完整下面的类定义： const double PI=3.14; class circle{ //圆形物体的抽象基类 protected: double r; //半径 public: Circle(double radius=0):r(radius){} ______; //计算圆形物体表面积的纯虚函数声明 }; class Cylinder: public Circle { //圆柱体类 double h;//高度 public: Cylinder(double radius=0,double height=0): Circle(radius),h(height){} virtual double Area( ){ //计算圆柱体的表面积 return 2*PI*r*(r+h); } };

15.补充完整下面的类定义： const double PI=3.14； class Circle{ //圆形物体的抽象基类 protected： double r； //半径 public： Circle(double radius=0)：r(radius){ } ______； //计算圆形物体表面积的纯虚函数声明 }； class Cylinder：public Circle{//圆柱体类 double h； //高度 public： Cylinder(double radius=0，double height=0)； Circle(radius)，h(height){ } Virtual double Area( ){return 2*PI*r*(r+h)；}//计算圆柱体的表面积 }；

16.public class Demo { public static void sum(int a, int b) { System.out.println("int:" + (a + b)); } public static void sum(int a, float b) { System.out.println("float:" + (a + b)); } public static void sum(int a, double b) { System.out.println("double:" + (a + b)); } public static void main(String[] args) { int a = 10; long b = 20; sum(a, b); }} 程序的运行结果是

17.public class Demo { public static void sum(int a, int b) { System.out.println("int:" + (a + b)); } public static void sum(int a, float b) { System.out.println("float:" + (a + b)); } public static void sum(int a, double b) { System.out.println("double:" + (a + b)); } public static void main(String[] args) { int a = 10; long b = 20; sum(a, b); }} 程序的运行结果是

18.以下程序执行结果为?public class My{ int value; public static void main(String args[]) { My x = new My(); My y = x; x.value+=1; System.out.println(y.value); } }

19.public class Example { public static void main(String[] args) { new Father () { public void show() { System.out.println("helloworld"); } }.show(); } } class Father { public void show() { System.out.println("hellofather"); } }

20.中国大学MOOC: 请阅读下面的程序：public class Demo { public static void sum(int a, int b) { System.out.println(int: (a b)); } public static void sum(int a, float b) { System.out.println(float: (a b)); } public static void sum(int a, double b) { System.out.println(double: (a b)); } public static void main(String[] args) { int a = 10; long b = 20; sum(a, b); }}

21.请阅读下面的程序：public class Demo { public static void sum(int a, int b) { System.out.println("int:" + (a + b)); } public static void sum(int a, float b) { System.out.println("float:" + (a + b)); } public static void sum(int a, double b) { System.out.println("double:" + (a + b)); } public static void main(String[] args) { int a = 10; long b = 20; sum(a, b); }} 选项： A、int:30 B、float:30.0 C、double:30.0 D、int:30.0

22.下面这段代码的输出结果是什么?class Fu {public int num =10;public Fu(){System.out.println("fu");}}class Zi extends Fu {public int num =20;public Zi(){System.out.println("zi");}public void show(){int num =30;System.out.println(num);System.out.println(this.num);System.out.println(super.num);}}class ExtendsTest {public static void main(String[]args){Zi z =new Zi();z.show();}}