CPA – Programming Essentials in C++ Chapter 2 Module 3

Question 1:

What is the output of the following snippet?
#include <iostream>
using namespace std;
class X {
public:
    X(void) { cout << 1; }
    ~X(void) { cout << 2; }
}; 
X *exec() {
    X *x = new X();
    throw string("0");
    return x;
}
   
int main(void) {
    X *x;
    try {
        delete exec();
    } catch(string &s) {
        cout << s;
    }
    return 0;

}
 
Answer: 10


Question 2: What is the output of the following snippet?
#include <iostream>
#include <exception>
   
using namespace std;
    
int main() {
    try {
        throw 2./4;
    }
    catch(int i) {
        cout << i;
    }
    return 0;
}
 
Answer: Execution fails


Question 3: What is the output of the following snippet?
#include <iostream>
#include <exception>
#include <stdexcept>
using namespace std;
    
class E {};
    
class X {
    static int c;
public:
    X() { if(c++ > 2) throw new E; }
    ~X() { if(c++ > 2) throw new E; }
};
    
int X::c = 0;
    
void f(int i) {
    X a,b;
    cout << i;
}
    
int main(void) {
    try {
        f(0);
        f(1);
    } catch(...) {
        cout << 1;
    }
    return 0;
}
 
Answer: 01


Question 4: What is the output of the following snippet?
#include <iostream>
#include <exception>
#include <stdexcept>
using namespace std;
    
class X : public runtime_error {
public:
    X() : domain_error("0") {};
};
    
void z() throw(X) {
    X x;
    throw x;
    cout << 1;
}
    
int main(void) {
    X x;
    try {
        z();
    } catch(X &i) {
        cout << 1;
    }
    catch(domain_error &i) {
        cout << 0;
    }
    return 0;
}
 
Answer: Compilation Fails


Question 5: What is the output of the following snippet?
#include <iostream>
#include <exception>
    
using namespace std;
    
int main() {
    throw 2/4;
    catch(int i) {
        cout << i;
    }
    return 0;
}
 
Answer: Compilation fails


Question 6: What is the output of the following snippet?
#include <iostream>
#include <exception>
#include <stdexcept>
using namespace std;
    
class X : public logic_error {
public:
    X() : logic_error("0") {};
};
    
void z() throw(logic_error) {
    X x;
    throw x;
    cout << 1;
}
    
int main(void) {
    X x;
    try {
        z();
    } catch(logic_error &i) {
        cout << i.what();
    }
    return 0;
}
 
Answer: 0


Question 7: What is the output of the following snippet?
#include <iostream>
using namespace std;
class X {
public:
    X(void) { cout << 0; }
    ~X(void) { cout << 2; }
};  
    
int main(void) {
    try {
        X *x = new X();
    throw true;
        delete x;
    } catch(bool s) {
        cout << s;
    }
    return 0;
}
 
Answer: 01
 
Question 8: What is the output of the following snippet?
#include <iostream>
#include <exception>
#include <stdexcept>
using namespace std;
  
class E {};
   
class X {
public:
    static int c;
    X(int a) { c = a; }
    ~X() { if(c++ > 2) throw new E; }
};
    
int X::c = 0;
  
void f(int i) {
    X* t[2];
    for(int j = 0; j < i; j++)
        t[j] = new X(i+1);
    for(int j = 0; j < i; j++)
        delete t[j];
}
    
int main(void) {
    try {
        f(2);
    } catch(...) {
        cout << X::c;
    }
    return 0;
}
 
Answer: 3


Question 9: What is the output of the following snippet?
#include <iostream>
#include <exception>
    
using namespace std;
   
int main() {
    try {
        throw exception();
    }
    catch(exception &x) {
        cout << x.what();
    }
    return 0;
}
 
Answer: It prints a non-empty string


Question 10: What is the output of the following snippet?
#include <iostream>
#include <exception>
#include <stdexcept>
using namespace std;
    
class X : public logic_error {
public:
    X() : logic_error("0") {};
};
    
void z() throw(X) {
    throw new logic_error("0");
}
    
int main(void) {
    X x;
    try {
        z();
    } catch(X &i) {
        cout << i.what();
    }
    return 0;
}
 
Answer: Execution Fail


Question 11: What is the output of the following snippet?
#include <iostream>
#include <exception>
#include <stdexcept>
using namespace std;
  
class E {};
  
void f(int i) {
    E e;
    switch(i) {
    case 0 : throw e;
    case 1 : throw &e;
    }
    cout << 0;
}
    
int main(void) {
    try {
        f(1);
    } catch(void *) {
        cout << 2;
    } catch(E*) {
        cout << 1;
    }
    return 0;
}
Answer: 2


Question 12: What is the output of the following snippet?
#include <iostream>
#include <exception>
#include <stdexcept>
using namespace std;
    
class Int {
public:
    int v;
    Int(int a) : v(a) {}
};
    
void a() {
    throw Int(1);
}
    
void b() {
    try {
        a();
    } catch(Int &i) {
        throw Int(i.v + 1);
    }
}
    
void c() {
    try {
        b();
    } catch(...) {
        throw;
    }
}
    
int main(void) {
    try {
        c();
    } catch(Int &i) {
        cout << i.v;
    }
    return 0;
}
 
Answer: 2


Question 13: What is the output of the following snippet?
#include <iostream>
#include <string>
using namespace std;
class X {
public:
    X(void) { cout << 1; }
    ~X(void) { cout << 2; }
};  
void exec() {
    {   
        X x;
    }
    throw string("0");
}
    
int main(void) {
    try {
        exec();
    } catch(string &s) {
        cout << s;
    }
    return 0;
}
 
Answer: 120


Question 14: What is the output of the following snippet?
#include <iostream>
using namespace std;
class X {
public:
    X(void) throw(int) { cout << 1; }
    ~X(void) throw(int) { cout << 2; }
    void exec() { throw 0; }
};  
    
void exec(X &x) {
    x.exec() ;
}
    
int main(void) {
    X x;
    try {
        exec(x);
    } catch(int &i) {
        cout << i;
    }
    return 0;
}
 
Answer:
102


Question 15: What is the output of the following snippet?
#include <iostream>
#include <exception>
#include <stdexcept>
using namespace std;
    
class E {};
    
void f(int i) {
    E e;
    switch(i) {
    case 0 : throw e;
    case 1 : throw &e;
    }
    cout << 0;
}
    
int main(void) {
    try {
        f(2);
    } catch(E*) {
        cout << 1;
    } catch(E) {
        cout << 2;
    }
    return 0;
}
 
Answer: 0

Question 16: What is the output of the following snippet?
#include <iostream>
#include <exception>
#include <stdexcept>
using namespace std;
    
class Int {
public:
    int v;
    Int(int a) : v(a) {}
};
    
void a() {
    throw 0;
}
    
void b() {
    try {
        a();
    } catch(int i) {
        throw Int(i + 1);
    }
}
    
void c() {
    try {
        b();
    } catch(...) {
        throw;
    }
}
    
int main(void) {
    try {
        c();
    } catch(Int &i) {
        cout << i.v;
    }
    return 0;
}
 
Answer: 1

Question 17: What is the output of the following snippet?
#include <iostream>
#include <exception>
#include <stdexcept>
using namespace std;
    
class X : public domain_error {
public:
    X() : domain_error("0") {};
};
    
void z() throw(X) {
    X x;
    throw x;
    cout << 1;
}
    
int main(void) {
    X x;
    try {
        z();
    } catch(X &i) {
        cout << 1;
    }
    catch(domain_error &i) {
        cout << 0;
    }
    return 0;
}
 
Answer: 1


Question 18: What is the output of the following snippet?
#include <iostream>
#include <exception>
using namespace std;
int main() {
    try {
        throw 3.14;
    }
    catch(double x) {
        x *= 2;
    }
    cout << x;
    return 0;

Answer: Compilation fails


Question 19: What is the output of the following snippet?
#include <iostream>
using namespace std;
class X {
public:
    X(void) throw(int) { cout << 1; }
    ~X(void) throw(int) { cout << 2; }
    void exec() { throw string("0"); }
};  
   
void exec(X x) {
    x.exec() ;
}
    
int main(void) {
    X x;
    try {
        exec(x);
    } catch(int &i) {
        cout << i;
    }
    return 0;
}
 
Answer: Execution Fails


Question 20: What is the output of the following snippet?
#include <iostream>
#include <exception>
    
using namespace std;
   
int main() {
    try {
        throw 2/4;
    }
    catch(int i) {
        cout << i;
    }
    return 0;
}
 
Answer: 0