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1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
第2题:
若有以下程序: #include<iostream> using namespace std; class A { private: int a; public: void seta(int x) { a=x; } void showa() { cout<<a<<","; } }; class B { private: int b; public: void setb(int x) { b=x; } void showb() { cout<<b<<",”; } }; class C:pUblic A,private B { private: int c; public: void setc(int x,int y,int z) { c=z; seta(x); setb(y); } void showc() { showa(); showb(); cout<<c<<end1; } }; int main() { Cc; c.setc(1,2,3); c.showc(); retrun 0; } 程序执行后的输出结果是
A.1,2,3
B.1,1,1
C.2,2,2
D.3,3,3
第3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4题:
若有以下程序: #include <iostream> using namespace std; class point { private: int x, y; public: point ( ) { x=0; y=0; } void setpoint(int x1,int y1) { x=x1; y=y1;
A.12,12
B.5,5
C.12,5
D.5,12
第5题:
若有以下程序: #include <iostream> using namespace std; class A { private: int a; public: void seta(int x) { a=x; } void showa() { cout<<a<<","; } }; class B { private: int b; public: void setb (int x) { b=x; } void showb() { cout<<b<<","; } }; class C :public A,private B { private: int c; public: void setc(int x, inc y, int z) { c=z; seta (x); setb (y); } void showc() { showa (); showb (); cout<<c<<end1; } }; int main () { C c; c. setc(1,2,3); c.showc(); return 0; } 程序执行后的输出结果是
A.1,2,3
B.1,1,1
C.2,2,2
D.3,3,3
第6题:
若有以下程序: #include <iostream> using namespace std; class Base { private: int a,b; public: Base(int x, int y) { a=x; b=y; } void show() { cout<<a<<", "<<b<<end1; } }; class Derive : public Base { private: int c, d; public: Derive(int x, int y, int z,int m):Base(x,y) { c=z; d=m; } void show() { cout<<c<<", "<<d<<end1; } }; int main ( ) { Base b(50,50) ,*pb; Derive d(10,20,30,40); pb=&d; pb->show {); return 0; }
A.10,20
B.30,40
C.20,30
D.50,50
第7题:
如下程序执行后的输出结果是【 】。
include <iostream>
using namespace std;
class Base
{
public:
Base(int x,int y)
{
a=x;
b=y;
}
void Show()
{
cout<<"Base: "<<a<< ',' <<b<<" ";
}
private:
int a,b;
};
class Derived : public Base
{
public:
Derived(int x, int y, int z) : Base(x,y),c(z) { }
void Show()
{
cout<<"Derived:"<<c<<end1;
}
private:
int c;
};
int main()
{
Base b(100,100),*pb;
Derived d(10,20,30);
pb=&b;
pb->Show();
pb=&d;
pb->Show();
return 0;
}
第8题:
阅读以下说明和C++代码,填入(n)处。
[说明]
以下C++代码使用虚函数实现了同一基类shape派生出来的Class rectangle、Class triangle、Class circle实现了计算矩形、圆形面积的计算。仔细阅读以下代码,将(n)处语句补充完整。
[代码5-1]
include<iostream.h>
define PI 3.14159
class shape {//基类
protected:
(1);
public:
(2);
(3);
};
[代码5-2]
class rectangle: public shape {
public:
rectangle (int x2,int y2,int r2): (4) {};
double area ( ) {return x*y; };
};
class circle: public shape {
public:
circle (int x3,int y3,int r3):(5){};
double area ( ) {return r*r*PI; };
};
[代码5-3]
void main ( )
{
rectangle r (10,20,0);
circle c (0,0,30);
shape (6);
cout<<"长方形面积="<<s1->area ( ) <<endl;
cout<<"圆形面积="<<s2->area ( ) <<endl;
}
[运行结果]
长方形面积=200
圆形面积=2827.43
第9题:
若有以下程序:#include <iostream>using namespace std;class A{private: int a;public: void seta(int x) { a=x; } void showa() { cout<<a<<","; }};class B{private: int b;public: void setb(int x) { b=x; } void showb() { cout<<b<<","; }};class C: public A, private B{private: int c;public: void setc(int x, int y, int z) { c=z; seta(x); setb(y); } void showc() { showa(); showb(); cout<<c<<end1; }};int main(){ C c; c.setc(1,2,3); c.showc(); return 0;}程序执行后的输出结果是( )。
A.1,2,3
B.1,1,1
C.2,2,2
D.3,3,3
第10题: