CPP Online Practice Questions and Answers

What will happen when you attempt to compile and run the code below, assuming that you enter the following sequence: 1 2 3 4 quit?

#include

#include

#include

#include

using namespace std;

templatestruct Out {

ostream and out;

Out(ostream and o): out(o){}

void operator() (const T and val ) {out<

int main ()

{

list l;

while(cin.good())

{

string s;

cin>>s;

if (s == "quit") break;

l.push_back(s);

}

for_each(l.begin(), l.end(), Out(cout));

return 0;

}

Program will output:

A. 1 2 3 4

B. 1 2 3 4 quit

C. 1

D. program runs forever without output

What happens when you attempt to compile and run the following code?

#include

#include

#include

#include

using namespace std;

void myfunction(int i) {

cout << " " << i;

}

int multiply (int a) {

return a*2;

}

int main() {

int t[] = { 10, 5, 9, 6, 2, 4, 7, 8, 3, 1 };

vector v1(t, t+10);

set s1(t, t+10);

transform(s1.begin(), s1.end(), v1.begin(), multiply);

transform(v1.begin(), v1.end(), s1.begin(), multiply);

for_each(s1.begin(), s1.end(), myfunction);

return 0;

}

Program outputs:

A. 20 10 18 12 4 8 14 16 6 2

B. 2 4 6 8 10 12 14 16 18 20

C. 4 8 12 16 20 24 28 32 36 40

D. compilation error

What happens when you attempt to compile and run the following code?

#include

using namespace std;

int main()

{

cout.setf(ios::hex, ios::basefield);

cout<<100.33<<" ";

cout.setf(ios::showbase);

cout<<100.33<<" ";

return 0;

}

Program outputs:

A. 64.21 64.21

B. 64.21 0x64.21

C. 0x64.21 0x64.21

D. 100.33 100.33

E. compilation error

What will happen when you attempt to compile and run the following code? Choose all that apply.

#include

#include

#include

#include

using namespace std;

class A {

int a;

public:

A(int a) : a(a) {}

int getA() const { return a; } void setA(int a) { this?>a = a; }

bool operator < (const A and b) const { return a

};

class F {

A val;

public:

F(A and v):val(v){}

bool operator() (A and v) {

if (v.getA() == val.getA()) return true;

return false;

}

};

int main() {

int t[] = { 10, 5, 9, 6, 2, 4, 7, 8, 3, 1 };

vector v1(t, t + 10);

set s1(t, t + 10);

A a(6); F f(a);

find_if(s1.begin(), s1.end(), f);

if (find_if(v1.begin(), v1.end(), f) !=v1.end()) {

cout<<"Found!\n";

} else {

cout<<"Not found!\n";

}

return 0;

}

A. it will compile successfully

B. it will display Found!

C. it will display Not found!

D. it will not compile successfully

What will happen when you attempt to compile and run the following code?

#include

using namespace std;

template

class A {

T_v;

public:

A(T v): _v(v){}

T getV() { return _v; }

};

int main()

{

A a(1);

cout << a.getV() <

return 0;

}

A. program will display:1

B. program will not compile

C. program will compile

D. program will cause runtime exception

What happens when you attempt to compile and run the following code?

#include

#include

#include

#include

#include

using namespace std;

int main()

{

deque mydeck;list mylist; vector myvector;

queue first; queue second(mydeck);

queue third(second); queue > fourth(mylist);

fourth.push(10);fourth.push(11);fourth.push(12);

queue > fifth(myvector);

fifth.push(10);fifth.push(11);fifth.push(12); // Line I

while(!fifth.empty())

{

cout<

fifth.pop(); // Line III

} while (!fourth.empty()) { cout << fourth.front() << " "; fourth.pop(); // Line IV } return 0; }

A. program outputs: 10 11 12 10 11 12

B. compilation error in line I

C. compilation error in line II

D. compilation error in line III

E. compilation error in line IV

What happens when you attempt to compile and run the following code?

#include

#include

using namespace std;

int main() {

int t[] = { 1, 1, 2, 2, 3, 3, 4, 4, 5, 5 };

string s[] = { "one", "one", "two", "two", "three","three", "four", "four", "five", "five"};

multimap m;

for (int i = 0; i < 10; i++) {

m.insert(pair(t[i], s[i]));

}

if (m.count(3) == 2) {

m.erase(3);

}

for (multimap::iterator i = m.begin(); i != m.end(); i++) {

cout << i?>first << " ";

}

return 0;

}

A. program outputs: 1 2 3 4 5

B. program outputs: 1 2 4 5

C. program outputs: 1 1 2 2 3 4 4 5 5

D. program outputs: 1 1 2 2 4 4 5 5

E. program outputs: one two three four five

What happens when you attempt to compile and run the following code?

#include

#include

#include

#include

using namespace std;

void myfunction(int i) {

cout << " " << i;

}

int main() {

int t[] = { 10, 5, 9, 6, 2, 4, 7, 8, 3, 1 };

set s1(t, t+10);

vector v1(s1.rbegin(), s1.rend());

swap(s1, v1);

for_each(v1.begin(), v1.end(), myfunction);

for_each(s1.begin(), s1.end(), myfunction);

return 0;

}

Program outputs:

A. 10 9 8 7 6 5 4 3 2 1 1 2 3 4 5 6 7 8 9 10

B. compilation error

C. 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10

D. 10 9 8 7 6 5 4 3 2 1 10 9 8 7 6 5 4 3 2 1

What happens when you attempt to compile and run the following code? Choose all possible answers.

#include

using namespace std;

class C {

public:

int _c;

C():_c(0){}

C(int c) { _c = c;}

C operator+=(C and b) {

C tmp; tmp._c = _c+b._c;

return tmp;

} };

ostream and operator<<(ostream and c, const C and v) {

c<

template

class A {

T_v;

public:

A() {}

A(T v): _v(v){}

T getV() { return _v; }

void add(T and a) { _v+=a; }

};

int main()

{

A b(2);

Aa (5);

a.add(C());

cout << a.getV() <

return 0;

}

A. program will display:5

B. program will not compile

C. program will compile

D. program will cause runtime exception

What will happen when you attempt to compile and run the following code?

#include

#include

#include

using namespace std;

int main(){

int t[] ={ 3, 4, 2, 1, 6, 5, 7, 9, 8, 0 };

vectorv(t, t+10);

set s1(v.begin(),v.end());

s1.insert(v.begin(),v.end());

pair::iterator,set::iterator> range;

range = s1.equal_range(6);

cout<<*range.first<<" "<<*range.second<

return 0;

}

The output will be:

A. 6 6

B. 5 7

C. 6 7

D. 1 5

E. 6 5