Consider the following code. Answer questions 1 to 4. This is a walkthrough question

#include

#include

using namespace std;

const int NT = 10;

const int NC = 2;

class Chocolate {

char type[NT + 1];

public:

Chocolate(const char* t = nullptr) {

if (t) {

strncpy(type, t, NT);

type[NT] = '\0';

}

else {

type[0] = '\0';

}

cout << "C";

}

~Chocolate() {

cout << "~" << type << endl;

}

void display() const {

cout << type << endl;

}

};

class Box {

Chocolate ch[NC];

int nc;

public:

Box() {

nc = 0;

cout << "B";

}

Box& operator+=(const Chocolate& c) {

if (nc < NC) {

ch[nc] = c;

cout << "+";

ch[nc++].display();

}

return *this;

}

Box(const Box& b) {

nc = b.nc;

for (int i = 0; i < nc; i++)

ch[i] = b.ch[i];

cout << "E" << endl;

}

~Box() {

cout << "~B" << endl;

}

void display() const {

for (int i = 0; i < nc; i++)

ch[i].display();

cout << endl;

}

};

void show(const Box b) {

b.display();

}

int main() {

cout << "=Chocolate=" << endl;

Chocolate cherry("cherry");

Chocolate orange("orange");

cout << " =Box=" << endl;

Box b;

cout << " =++=" << endl;

b += orange;

b += cherry;

cout << " =show=" << endl;

show(b);

cout << " =done=" << endl;

return 0;

}

1- Explain what the operator Box& operator+=(const Chocolate& c) does.

2- How can you improve the performance the show() function in this program. Explain the effect of your upgrade in one or two sentences.

3- Explain in one or two sentences the meaning of the keyword const in the display()function.

4- Describe in one or two sentences the effect of removing the default parameter value in the definition of the Chocolate() constructor.