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;
int main() {
float i = 1.0 / 2 * 2 / 1 * 2 / 4 * 4 / 2;
cout << i;
return 0;
}
A. It prints: 2
B. It prints: 0
C. It prints: 1
D. It prints: 0.5
正解：C

質問 2：
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 3：
What is the output of the program?
#include <iostream>
#include <string>
using namespace std;
int main()
{
string s1[]= {"H" , "t" };
string s;
for (int i=0; i<2; i++) {
s = s1[i];
if (i==0)
s.insert(1,"ow");
else
s.push_back('o');
cout << s;
}
return( 0 );
}
A. It prints: Howto
B. It prints: Hoto
C. It prints: toHo
D. It prints: Ht
正解：A

質問 4：
If there is one, point out an error in the program
#include <iostream>
using namespace std;
int main() {
int c = 'a';
switch(i)
{
case '2':
cout<<"OK";
case '1':
cout<<"Error";
default:
break;
}
return 0;
}
A. No Error
B. Illegal use of 'continue'
C. Illegal use of 'break'
D. Use of undeclared identifier 'i'
正解：D

質問 5：
Which code, inserted at line 18, generates the output "AB"
#include <iostream>
using namespace std;
class A
{
public:
void Print(){ cout<< "A";}
void Print2(){ cout<< "a";}
};
class B:public A
{
public:
void Print(){ cout<< "B";}
void Print2(){ cout<< "b";}
};
int main()
{
B ob2;
//insert code here ob2.Print(); }
A. ob2->A::Print();
B. ob2.B::Print();
C. ob2.A::Print();
D. ob2->B::Print();
正解：C

質問 6：
What is the output of the program?
#include <iostream>
#include <string>
using namespace std;
class First
{
string name;
public:
First() {
name = "Alan";
}
void Print(){
cout << name;
}
};
int main()
{
First ob1,*ob2;
ob2 = new First();
ob1.Print(); ob2->Print(); }
A. Garbage value
B. It prints: Al
C. It prints: AlanAlan
D. It prints: Alan
正解：C

質問 7：
What happens when you attempt to compile and run the following code?
#include <iostream>
using namespace std;
class A {
public:
void Print(){ cout<<"A";}
};
class C:public A {
public:
virtual void Print()=0;
};
int main()
{
C obj3;
obj3->Print();
}
A. It prints: A
B. It prints: AB
C. Compilation error
D. It prints: BB
正解：C

質問 8：
What is the output of the program?
#include <iostream>
using namespace std;
#define SQR(x)(x*x)
int main(int argc, char *argv[]) {
int x, y=2;
x = SQR(y);
cout << x << ", " <<y;
return 0;
}
A. It prints: 9, 2
B. It prints: 3, 3
C. It prints: 3, 2
D. It prints: 4, 2
正解：D