static class InnerOne { public double methoda() {return d1;} }
static class InnerOne { static double methoda() {return d1;} }
private class InnerOne { public double methoda() {return d1;} }
protected class InnerOne { static double methoda() {return d1;} }
public abstract class InnerOne { public abstract double methoda(); }
第1题:
A.double getSalesAmount() { return 1230.45; }
B.public double getSalesAmount() { return 1230.45; }
C.private double getSalesAmount() { return 1230.45; }
D.protected double getSalesAmount() { return 1230.45; }
第2题:
下列程序的执行结果为【 】。
include <iostream. h>
class Point
{
public:
Point(double i, double j) { x=i; y=j;}
double Area() const { return 0.0;}
private:
double x, y;
};
class Rectangle: public Point
{
public:
Rectangle(double i, double j, double k, double 1)
double Area() const {return w * h;}
private:
double w, h;
};
Rectangle: :Rectangle(double i, double j, double k. double 1): Point(i,j).
{
w=k, h=1
}
void fun(Point &s)
{
cout<<s. Area()<<end1;
}
void main( )
{
Rectangle rec(3.0, 5.2, 15.0. 25.0);
fun(rec)
}
第3题:
下列成员变量声明中,正确的是______。
A.public protected final int i;
B.abstract class F1{…}
C.private double height;
D.double weight
第4题:
下列选项成员变量声明正确的是( )。
A.public protected final int i;
B.abstract class Fl{…}
C.private double height;
D.double weight
第5题:
有如下两个类定义: class XX{ private: double xl; protected: double x2; public: double x3; }; class YY:protected XX{ private: double yl; protected: double y2; public: double y3; 在类YY中保护成员变量的个数是( )。
A.1
B.2
C.3
D.4
第6题:
1. class BaseClass { 2. private float x = 1.of; 3. protected float getVar() { return x; } 4. } 5. class SubClass extends BaseClass { 6. private float x = 2.Of; 7. // insert code here 8. } Which two are valid examples of method overriding when inserted at line 7?()
第7题:
Which three demonstrate an “is a” relationship?()
第8题:
public class OuterClass { private double d1 1.0; //insert code here } You need to insert an inner class declaration at line2. Which two inner class declarations are valid?()
第9题:
Which the two demonstrate an “is a” relationship?()
第10题:
public class Car { private int wheelCount; private String vin; public Car(String vin) { this.vin = vin; this.wheelCount = 4; } public String drive() { return “zoom-zoom”; } public String getInfo() { return “VIN: “+ vin + “wheels: “+ wheelCount; } } And: public class MeGo extends Car { public MeGo(String vin) { this.wheelCount = 3; } } What two must the programmer do to correct the compilation errors?()
第11题:
Abstract public void methoda();
Public abstract double methoda();
Static void methoda(double d1){}
Public native double methoda() {}
Protected void methoda(double d1) {}
第12题:
static class InnerOne { public double methoda() {return d1;} }
static class InnerOne { static double methoda() {return d1;} }
private class InnerOne { public double methoda() {return d1;} }
protected class InnerOne { static double methoda() {return d1;} }
public abstract class InnerOne { public abstract double methoda(); }
第13题:
阅读以下函数说明和Java代码,将应填入(n)处的字句写在对应栏内。
【说明】
下面的程序先构造Point类,再顺序构造Ball类。由于在类Ball中不能直接存取类Point中的xCoordinate及yCoordinate属性值,Ball中的toString方法调用Point类中的toStrinS方法输出中心点的值。在MovingBsll类的toString方法中,super.toString调用父类Ball的toString方法输出类Ball中声明的属性值。
【Java代码】
//Point.java文件
public class Point{
private double xCoordinate;
private double yCoordinate;
public Point(){}
public Point(double x,double y){
xCoordinate=x;
yCoordinate=y;
}
public String toStrthg(){
return"("+Double.toString(xCoordinate)+","
+Double.toString(yCoordinate)+")";
}
//other methods
}
//Ball.java文件
public class Ball{
private (1);//中心点
private double radius;//半径
private String color;//颜色
public Ball(){}
public Ball(double xValue, double yValue, double r){
//具有中心点及其半径的构造方法
center=(2);//调用类Point中的构造方法
radius=r;
}
public Ball(double xValue, double yValue, double r, String c){
//具有中心点、半径和颜色的构造方法
(3);//调用3个参数的构造方法
color=c;
}
public String toString(){
return "A ball with center"+center.toString()
+",radius "+Double.toString(radius)+",color"+color;
}
//other methods
}
class MovingBall (4) {
private double speed;
public MovingBall(){}
public MoyingBall(double xValue, double yValue, double r, String c, double s){
(5);//调用父类Ball中具有4个参数的构造方法
speed=s;
}
public String toString(){
return super.toString()+",speed"+Double.toString(speed);
}
//other methods
}
public class test{
public static void main(String args[]){
MovingBall mb=new MovingBall(10,20,40,"green",25);
System.out.println(mb);
}
}
第14题:
下列选项成员变量声明正确的是
A.public protected final int i;
B.abstract class F1{…}
C.private double height;
D.double weight{}
第15题:
有以下程序: #include<iostream> using namespace std; class sample { private: int x; public: sample(int A) { x=a; friend double square(sample s); }; double square(sample s) { return S.X*S.K; } int main() { sa
A.20
B.30
C.900
D.400
第16题:
有以下程序: #include<iostream> #include<math> using namespace std; class point { private: double x; double y; public: point(double a,double B) { x=a; y=b; } friend double distance (point a,point B) ;
A.1
B.5
C.4
D.6
第17题:
第18题:
Which will declare a method that is available to all members of the same package and can be referenced without an instance of the class?()
第19题:
10. abstract public class Employee { 11. protected abstract double getSalesAmount(); 12. public double getCommision() { 13. return getSalesAmount() * 0.15; 14. } 15. } 16. class Sales extends Employee { 17. // insert method here 18. } Which two methods, inserted independently at line 17, correctly complete the Sales class?()
第20题:
class BaseClass{ private float x= 1.0f; protected void setVar (float f) {x = f;} } class SubClass extends BaseClass { private float x = 2.0f; //insert code here } Which two are valid examples of method overriding?()
第21题:
1. public class OuterClass { 2. private double d1 = 1.0; 3. // insert code here 4. } Which two are valid if inserted at line 3?()
第22题:
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?()
第23题:
static class InnerOne { public double methoda() { return d1; } }
static class InnerOne { static double methoda() { return d1; } }
private class InnerOne { public double methoda() { return d1; } }
protected class InnerOne { static double methoda() { return d1; } }
public abstract class InnerOne { public abstract double methoda(); }
第24题:
double getSalesAmount() { return 1230.45; }
public double getSalesAmount() { return 1230.45; }
private double getSalesAmount() { return 1230.45; }
protected double getSalesAmount() { return 1230.45; }