阅读下面程序: import javax.swing.JOptionPane; public class Comparison { public static void main (Stringargs[]){ String firstNumber, //用户输入第1个数据变量 secondNumber, //用户输入第2个数据变量 result; //输出结果变量 mtnumberl, //用于比较的第1个数 number2; //用于比较的第2个数 //用户输入第1个数据的字符串 firstNumber=JOptionPane.showlnputDialog(“输入第1个整数:”) //用户输入第2个数据的字符串 secondNumber=JOptionPane。showlnputDialog(“输入第2个整数:”); //将字符串转换为整数类型 number1=Integer.parseInt(firstNumber); number2=Integer.parseInt(secondNumber); //初始化结果变量 _________________________; //比较两个数据 if(number1=number2) result+=numberl+"="+number2; if(number1 !=number2) resun+=numberl+"!="+number2; if(number1<number2) result=result+"\n"+number1+"<"+nunlber2; if(number1>number2) result=result+"\n"+numberl+">"+number2; if(numberl<=number2) result二reSUlt+”h1”+numberl+”仁”+number2; if(number1>=number2) result=result+"\n"+number1+">="+number2; //显示结果 JOpdonPane.showMessageDialog(null,rcsult, "比较结果", JOpdonPane.INFORMATION_MESSAGE; System,exIT(0); } } 为使程序能正确运行并得到合理的输出结果,初始化结果变量语句(下划线处)应是 ( )。
A.result=""
B.resnlt=null
C.resun=number1
D.result=number2
第1题:
下面程序运行时输出结果为【 】。
include<iostream.h>
include<malloc.h>
class Rect
{
public:
Rect(int1,int w)(length=1;width=w;)
void Print(){cout<<"Area:"<<length *width<<endl;)
void *operator new(size-t size){return malloc(size);}
void operator delete(void *p){free(p)
private:
int length,width;
};
void main()
{
Rect*p;
p=new Rect(5,4);
p->Print();
delete p;
}
第2题:
将下面程序补充完整。
include <iostream>
using namespace std;
class Base{
public:
【 】 fun(){return 0;} //声明虚函数
};
class Derived:public Base{
public:
x,y;
void SetVal(int a,int b){}
int fun(){return x+y;}
};
void 【 】 SetVal(int a,int b){x=a;y=b;} //类Derived成员函数
void main(){
Derived d;
cout<<d.fun()<<endl;
}
第3题:
有如下程序: #include<iostream.h> using namespace std; Class Base { public: Base(){cout<<“BB”;f();} void{(){cout<<“BF”;} }; class Derived:public Base { public: Derived(){cout<<“DD”;} void f(){cout<<“Df”;) }; int main
A.BBBfDD
B.BBDfDDDf
C.DD
D.DDBBBf
第4题:
第5题:
下面程序的结果是 ______。 #include<iostream.h> class A{ public: virtual void fun()=0{}; }; class B:public A{ public: void fun () {cout<< "new file" ;} }; class C: public A{ public: void fun (){cout<<"open file"<< " " } }; class D: public A{ public: void fun () {cout<< "save file\n" ;} }; void main() { A a,*p; B b; C c; D d; p=&c; p->fun (); p=&b; p->fun (); p=&d; p->fun(); }
A.new file open file save file
B.new file new file new file
C.编译出错
D.open file new file save file
第6题:
在下面程序中,括号里应填( )。 #include <iostream> using namespace std; class A { public: void fun( ) { cout << "Hello" << endl; } }; class B:: public A { void fun( ) { ( ) //调用基类的函数fun( ) tout << "HI" << endl; } };
A.fun()
B.A. fun()
C.A::fun()
D.A->fun(
第7题:
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();
}
第8题:
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::data
void main(void)
{
SomeClass my_class(1001),your_class(2002);
your_class. set_data(4004);
my_elass. show_data()
}
第9题:
第10题:
阅读下面的程序, 写出运行后输出的结果。 #include<iostream> using namespace std; class A { public: A(){cout<<"A";} }; class B :public A { public: B(){cout<<"B";} }; void main() { B b1; }