import java.awt.*
package local.util
class MoreInteresting{}
protected class MoreInteresting{}
第1题:
在下面Java Applet程序的下画线处填入代码,使程序完整并能够正确运行。
import java.applet.*;
import java.awt.*;
public class HelloWorld ______ {
public void paint(Graphics g) {
g.drawString("Hello World!",25,25);
}
}
第2题:
有如下类定义:
class Point{
public:
Point(int xx=0,int yy=0):x(xx),y(yy) { }
private:
int x,y;
};
class Circle:public Point{
public:
Circle(int r):radius(r) { }
private:
int radius;
};
派生类Circle中数据成员的个数是( )。
A、3
B、1
C、5
D、2
答案:A
解析:本题考查默认构造函数和带参数的构造函数,题目中定义一个对象a(2)以及对象数组b[3],共执行3次构造函数,对象指针不调用构造函数。
第3题:
A.importjava.awt.*
B.packagelocal.util
C.classMoreInteresting{}
D.protectedclassMoreInteresting{}
第4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5题:
下列哪个选项的java源文件代码片段是不正确的?
A.package testpackage; public class Test{ }
B.import java. io. *; package testpaekage; public class Test { }
C.import java.io.*; class Person { } public class Test { }
D.import java.io.*; import java. awt.*; public class Test{ }
第6题:
A.public class test { public int x = 0; public test(int x) { this.x = x; } }
B.public class Test{ public int x=0; public Test(int x) { this.x = x; } }
C.public class Test extends T1, T2 { public int x = 0; public Test (int x) { this.x = x; } }
D.public class
第7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8题:
将下面Applet程序补充完整。
import java.awt.*:
import java.apptet.*;
public class Hi ______ {
public void paint(Graghics g) {
g.drawstring("Hi!",2.5,2.5);
}
}
第9题:
在下列源代码文件Test.java中,正确定义类的代码是( )。
A.pblic class test { public int x=0; public test(int x) { this. x=x;} }
B.public class Test { public int x=0; public Test(int x) { this. x=x;} }
C.public class Test extends T1,T2{ public int x = 0; public Test(int x){ this. x = x; } }
D.protected class Test extends T2{ public int x = 0; public Test(int x) { this. x = x; } }
第10题:
有以下程序: #include<iostream> using namespace std; #definePl 3.14 Class Point {private: int x,y; public: Point(int a,intB) {X=a; y:b;} int getx() <return x;} int gety() {return y;}}; class Circle:public Point {pri
A.314
B.157
C.78.5
D.153.86