下面的代码中有什么错误吗？_______using System;class A{public virtual void F(){Console.WriteLine("A.F");}}abstract class B:A{public abstract override void F();
下面的代码中有什么错误吗？_______
using System;
class A
{
public virtual void F(){
Console.WriteLine("A.F");
}
}
abstract class B:A
{
public abstract override void F();
相关考题：
下列程序的运行结果是【 】。 include class SomeClass { public: SomeClass(int va 下列程序的运行结果是【 】。include ＜iostream. h＞class SomeClass{public:SomeClass(int value) { some_value=value;};void show_data(void) { cout＜＜data＜＜"＜＜~some_value＜＜endl; };static void set_data(int value) {data=value; }private:static int data;int some_value};int SomeClass::datavoid main(void){SomeClass my_class(1001),your_class(2002);your_class. set_data(4004);my_elass. show_data()}
下列程序编译时发现pb－>f(10);语句出现错误,其原因是______。 include class Base { 下列程序编译时发现pb-＞f(10)；语句出现错误，其原因是______。include＜iostream.h＞class Base{public:void f(int x){cout＜＜"Base:"＜＜x＜＜endl;)};class Derived:public Base{public:void f(char*str){cout＜＜"Derived:"＜＜str＜＜endl;}};void main(void){Derived*pd=new Derived;Pd-＞f(10);}
请写出下面的输出：class B{public:virtual void Print(void){printf(“B::Print\n”);}virtual void Reprint(void){printf(“B:Reprint\n”);}void Algo(void){Print();Reprint();}};class D : public B{public:virtual void Print(void){printf(“D::Print\n”);}};void main(){B *p = new D();p-Print();p-Algo();}
阅读以下说明和Java程序，填写程序中的空（1）～（6），将解答写入答题纸的对应栏内。【说明】以下Java代码实现一个简单绘图工具，绘制不同形状以及不同颜色的图形。部分接口、类及其关系如图5－1所示。【Java代码】interface?DrawCircle?{? //绘制圆形 public（1） ；}class?RedCircle?implements?DrawCircle?{? ?//绘制红色圆形???????public?void?drawCircle(int?radius,intx,?int?y)??{????????????System.out.println("Drawing?Circle[red,radius:"?+?radius?+",x:"?+?x?+?",y:"?+y+?"]");???????}}class?GreenCircle?implements?DrawCircle?{????//绘制绿色圆形??????public?void?drawCircle(int?radius,?int?x,int?y)?{???????????System.out.println("Drawing?Circle[green,radius:"?+radius+",x:?"?+x+?",y:?"?+y+?"]");??????}}abstract?class?Shape?{????//形状? protected? ? （2）???;? ? public?Shape(DrawCircle?drawCircle)?{? ?this.drawCircle=?drawCircle;? ? ? public?abstract?void?draw();}class?Circle?extends?Shape?{? //圆形? ?private?int?x,y,radius;? public?Circle(int?x,int?y,intradius,DrawCircle?drawCircle)?{? ?（3）???;? this.x?=?x;? ? ? this.y?=?y;? ?this.radius?=radius;? }? ? ?public?void?draw()?{? ? drawCircle.? ?（4）? ?;? ? ? }}public?class?DrawCircleMain?{? public?static?void?main(String[]?args)?{? Shape?redCircle＝new?Circle(?100,100,10,? （5） )；//绘制红色圆形? Shape?greenCircle＝new?Circle(200,200,10,（6） )；//绘制绿色圆形? ?redCircle.draw(); greenCircle.draw();? ?}}
阅读下列说明和C++代码，填写程序中的空（1）～（6），将解答写入答题纸的对应栏内。【说明】以下C++代码实现一个简单绘图工具，绘制不同形状以及不同颜色的图形。部分类及其关系如图6－1所示。【C++代码】#include?#include?using?namespace?std;class?DrawCircle?{??????//绘制圆形，抽象类? ? ? public: （1）；//定义参数为?int?radius,?int?x,?inty? ?virtual～DrawCircle()?{?}};class?RedCircle：public?DrawCircle?{????//绘制红色圆形? ? ? ? public: void?drawCircle(intradius,?int?x,?int?y)?{cout??drawCircle?=?drawCircle;? }? ?virtual～shape()?{?}? public:? ?virtual?void?draw()?=?0;};class?Circle：public?Shape?{????//圆形? ? private:? ? ?int?x,y,radius;? ? public:? Circle(int?x,inty,int?radius,DrawCircle?*drawCircle)? （3）? {? this->x?=?x;? ?this->y?=?y;? ? this->radius?=?radius; }? ? ? public:? void?draw(){? drawCircle?-> （4）; }};int?main(){Shape?*redCirclenew?Circle(100,100,10,????（5）????);//绘制红色圆形? Shape?*greenCircle＝new?Circle(100,100,10, （6）??);//绘制绿色圆形redCircle >draw();? ?greenCircle?->draw();? ?return?0;}
阅读下列代码,选出该代码段正确的文件名（)。 class A{ void method1（){ System.out.println（"Method1 in class A"); } } public class B{ void method2（){ System.out.println（"Method2 in class B"); } public static void main（String[] args){ System.out.println（"main（) in class B"); } }A．javaB．A.classC．B.javaD．B.class
消除下述代码 compile 阶段语法错误的方式为 class A { public: virtual int f（) = 0; }; int main（) { A a; （a) -＞ f（); }A．将第3行代码中的virtual关键字去掉B．将第3行代码中的 = 0; 改为 {}C．将第6行及第7行代码删除D．将第7行改为 a.f();E．将第3行代码中的 = 0 去掉