C++ Institute CPA 問題集

質問 1：
What happens when you attempt to compile and run the following code?
#include <iostream>
using namespace std;
class First
{
public:
virtual void Print(){ cout<<"from First";}
};
class Second:public First
{
public:
void Print(){ cout<< "from Second";}
};
void fun(First *obj);
int main()
{
First FirstObject;
fun(&FirstObject);
Second SecondObject;
fun(&SecondObject);
}
void fun(First *obj)
{
obj->Print();
}
A. It prints: from Secondfrom Second
B. It prints: from Firstfrom Second
C. It prints: from First
D. It prints: from Firstfrom First
正解：B

質問 2：
What happens when you attempt to compile and run the following code?
#include <iostream> #include <string>
using namespace std;
class complex{
double re, im;
public:
complex() : re(1),im(0.4) {}
complex operator+(complex &t);
void Print() { cout << re << " " << im; }
};
complex complex::operator+ (complex &t){
complex temp;
temp.re = this->re + t.re;
temp.im = this->im + t.im;
return temp;
}
int main(){
complex c1,c2,c3;
c3 = c1 + c2;
c3.Print();
}
A. Garbage value
B. It prints: 0 0
C. It prints: 2 0.8
D. It prints: 1 0.4
正解：C

質問 3：
What will the variable "y" be in class B?
class A {
int x;
protected:
int y;
public:
int age;
};
class B : protected A {
string name;
public:
void Print() {
cout << name << age;
}
};
A. public
B. protected
C. None of these
D. private
正解：B

質問 4：
What happens when you attempt to compile and run the following code?
#include <iostream>
using namespace std;
int main()
{
int x=2, *y;
y = &x;
cout << *y + x;
return 0;
}
A. It prints: 4
B. It prints: 2
C. It prints: 0
D. It prints: 1
正解：A

質問 5：
What happens when you attempt to compile and run the following code?
#include <iostream>
using namespace std;
class A { public: virtual void Print()=0; }; class B:public A {
public:
virtual void Print(){ cout<< "B";}
};
int main()
{
B ob2;
A *obj;
obj = &ob2;
obj->Print();
}
A. It prints: A
B. It prints: BA
C. It prints: AB
D. It prints: B
正解：D

質問 6：
What is the output of the program?
#include <iostream>
#include <string>
using namespace std;
int main()
{
char str[] = "Hello\0\World\0";
cout << str;
return 0;
}
A. It prints: World\0World
B. It prints: HW
C. It prints: Hello
D. It prints: World
正解：C

質問 7：
Which definitions are correct?
A. char c;
B. int char;
C. int age;
D. int double;
正解：A,C

質問 8：
What is the output of the program?
#include <iostream>
using namespace std;
class BaseC
{
int i;
public:
BaseC() { i=?1;}
BaseC(int i) { i=i; }
void seti(int a) { i = a; };
void Print() { cout << i; }
};
int main()
{
BaseC *o = new BaseC();
o->seti(10);
o->Print();
}
A. It prints: 10
B. It prints: 0
C. Compilation error
D. It prints: ?1
正解：A