What does the following UML diagram entry mean? + setHeight(h : double

1.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

2.package hjkgk;public class Rectangle {public double width;public double height;public double getSize(　　) {return 2 * (width + height);}public double getArea(　　) {return width * height;}public static void main(String] args) {Rectangle rectangle = new Rectangle(　　);rectangle.width = 20;rectangle.height= 10;System.out.println(　　)); System.out.println(　　));}}package hjkgk;public class Rectangle {public double width;public double height;public double getSize(　　) {return 2 * (width + height);}public double getArea(　　) {return width * height;}public static void main(String] args) {Rectangle rectangle = new Rectangle(　　);rectangle.width = 20;rectangle.height= 10;System.out.println(　　)); System.out.println(　　));}}

3.程序的输出结果是： class Program { static void Main(string[] args) { Triangle t = new Triangle(3, 4); double s = t.area(); Console.WriteLine("area is {0}",s); Console.ReadLine(); } } class Shape { protected double width; protected double height; public Shape() { width = height = 0; } public Shape(double w, double h) { width = w; height = h; } public virtual double area() { return width * height; } } class Triangle : Shape { public Triangle(double x, double y) : base(x, y) { } public override double area() { return width * height / 2; } }

4.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.

5.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.

6.Read the following program:int fun1(double a) { return a*=a;}int fun2(double x,double y){double a=0,b=0;a=fun1(x); b=fun1(y); return (int)(a+b);}if w is a variable of type double, what is the value of w, after executing the statement w=fun2(1.1,2.0);? 选项： A:5.21; B:5; C:5.0; D:0.0

7.Read the following program:int fun1(double a) { return a*=a;}int fun2(double x,double y){double a=0,b=0;a=fun1(x);b=fun1(y);return (int)(a+b);}if w is a variable of type double, what is the value of w, after executing the statement w=fun2(1.1,2.0);? 选项： A:5.21; B:5.0; C:5; D:0.0

8.“图形”类Shape中定义了纯虚函数CalArea()，“三角形”类Triangle继承了类Shape，请将Triangle类中的CalArea函数补充完整。 #include using namespace std;class Shape{ public: virtual double CalArea()=0; //求面积}; class Triangle: public Shape{ public: Triangle(double s, double h):side(s),height(h){} ________________{ return side * height/2;} //求三角形面积private: double side;//底边长 double height; //底边上的高}; int main(){ Triangle tri(3,5); cout<<"Triangle area="<

9.“图形”类Shape中定义了纯虚函数CalArea()，“三角形”类Triangle继承了类Shape，请将Triangle类中的CalArea函数补充完整。 #include using namespace std;class Shape{ public: virtual double CalArea()=0; //求面积}; class Triangle: public Shape{ public: Triangle(double s, double h):side(s),height(h){} ________________{ return side * height/2;} //求三角形面积private: double side;//底边长 double height; //底边上的高}; int main(){ Triangle tri(3,5); cout<<"Triangle area="<

10.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；

11.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 }；

12.下面是一个有关几何图形类的程序,请补充完整_;(1)public class Geometric {private String color;private boolean filled;private Date date;public Geometric(){date =new Date();}public Geometric(String color,boolean filled){this.color =color;this.filled =filled;_;(2)//获取系统时间}public void setColor(String color){this.color =color;}public String getColor(){return color;}public void setFilled(boolean filled){this.filled =filled;}_{(3)//获取是否填充的方法return filled;}public Date getDate(){return date;}public String toString(){return "颜色:"+color +",是否填充:"+filled +",创建时间:"+date ;}public double getArea(){return 0;}}//圆类继承图形类public class Circle _(4){private double radius;public Circle(){}public Circle(double radius,String color,boolean filled){_;(5)this.radius =radius;}public double getRadius(){return radius;}public void setRadius(double radius){this.radius =radius;}public double getArea(){return radius*radius*Math.PI;}public double getPerimeter(){return 2*radius*Math.PI;}public double getDiameter(){return 2*radius;}@_(6)//判断是否是方法的重写public String toString(){return "圆形:【半径为:"+radius +",颜色为:"+getColor()+",是否填充"+isFilled()+",创建时间:"+getDate();}}//长方形类继承图形类public class Rectangle _{(7)private double length;private double width;public Rectangle(){_;(8)//调用父类构造方法}public Rectangle(String color,boolean filled,double length,double width){super(color,filled);this.length =length;this.width =width;}public double getLength(){return length;}public void setLength(double length){this.length =length;}public double getWidth(){return width;}public void setWidth(double width){this.width =width;}public double getArea(){_;(9)}public double getPerimeter(){return 2*(length+width);}@Override public String toString(){return "长方形【长:"+length +"宽:"+width +super.toString()+"】";}}//测试类public class Test {public static void main(String[]args){Geometric g =_;//(10)利用上转型使父类对象指向圆类对象,使用无参构造g =_;//(11)利用上转型使父类对象指向长方形对象,使用无参构造Rectangle re;if (g _){//(12)判断g是否属于长方形类re =_;//(13)对象下转型}else {System.out.println("类型不匹配");}}}

14.下列哪个成员变量声明是正确的 ( ) 选项： A、A) public protected final int i; B、B) abstract class F9 ... C、C) private double height; D、D) double weight

15.Design a class named Cylinder:1. The Cylinder class is a subclass of Circle,(you should not write this class ,it is the same as question 8),the Cylinder Class contains:2. A double data fields named h represents the high of Cylinder;3. A non-arg constructor that initalizes r with 1,h with 2;4. A constructor with 2 aguments that initalizes r and h with the arguments;5. A method named getVolume() that returns the volume of the Cylinder.

16.Which Data Element Type would you use in a data element to capture the tracking code from the URL? Select the correct answer. 选项：A、 Query String parameter B、 Session Storage C、 DOM Attribute D、 Custom Code

17.class Super{public float getNum(){return 3.0f;}} public class Sub extends Super{ //overload } which method, placed at overload, will cause a compiler error? 选项：A.public void getNum(double d){} B.public void getNum(){} C.public float getNum(){return 4.0f;} D.public double getNum(float d){return 4.0d;}

18.public String toString(double weight, double height){ double b = weight/(height*height); if(b < 20) return "偏瘦"; else if(b < 25) return "正常"; else if(b < 30) return "偏胖"; else if(b < 35) return "肥胖"; else if(b < 40) return "重度肥胖"; else return "极度肥胖";}如果采用等价类测试方法，最少要为这个程序设计______ 组测试数据？

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

20.public String toString(double weight, double height){ double b = weight/(height*height); if(b < 20) return "偏瘦"; else if(b < 25) return "正常"; else if(b < 30) return "偏胖"; else if(b < 35) return "肥胖"; else if(b < 40) return "重度肥胖"; else return "极度肥胖";}如果采用等价类测试方法，最少要为这个程序设计几组测试数据？

21.下列选项中，（）放在 //插入代码处会引起编译不通过？ class Super{ public int getValue() { return 2019; } } public class Sub extends Super{ //插入代码处 } 选项： A:public void getValue(int a) { }; B: public double getValue(double a,double b) { return a+b;} ; C:public void getValue() { } ; D:public int getValue() {return 2016;}

22.请依次写出【代码】处输出的内容。注意：答案之间用英文分号隔开interface A{ final static double PI=3.14; public default double area(int r){ return r*r*PI; } abstract double volume(int r,double h); public static String show(){ return "我是接口的静态方法"; }}public class E implements A{ public static void main(String[] args) { E c=new E(); System.out.print("柱体体积为："); System.out.println(c.volume(1,2.0)); // 【代码1】 System.out.println(A.show()); // 【代码2】 } public double area(int r){ return r*r; } public double volume(int r,double h){ return area(r)*h; }}