9.15. Coding Practice — How to Think Like a Computer Scientist

Write the Cake structure, which has instance variables name, color, diameter, and has_icing.

Below is one way to implement the program. We declare the Cake struct and list the instance variables in order.

Write the makeCake function, which prompts the user for a name, color, diameter, and whether or not they want icing. The function then returns the cake.

#include <iostream>
using namespace std;

struct Cake {
    string name;
    string color;
    double diameter;
    bool has_icing;
};

void printCakeInfo (Cake c);

// Write your code for the makeCake function here.

int main() {
    Cake input = makeCake ();
    printCakeInfo (input);
}
====
void printCakeInfo (Cake c) {
    if (c.name == "n/a") {
        if (c.has_icing) {
            cout << "This is a " << c.color << "," << c.diameter << " inch diameter cake with icing." << endl;
        }
        else {
            cout << "This is a " << c.color << "," << c.diameter << " inch diameter cake without icing." << endl;
        }
    }
    else {
        if (c.has_icing) {
            cout << "Happy birthday " << c.name << "! Your cake is " << c.color << ", has a " << c.diameter << " inch diameter, and comes with icing." << endl;
        }
        else {
            cout << "Happy birthday " << c.name << "! Your cake is " << c.color << ", has a " << c.diameter << " inch diameter, and comes without icing." << endl;
        }
    }
}

Below is one way to implement the program. We create a Cake for the user, read in the user’s input using cin, and return the Cake.

#include <iostream>
using namespace std;

struct Cake {
    string name;
    string color;
    double diameter;
    bool has_icing;
};

void printCakeInfo (Cake c);

Cake makeCake () {
    Cake input;
    string name, color;
    double diameter;
    char icing;
    cout << "Name: ";
    cin >> name;
    input.name = name;
    cout << "Color: ";
    cin >> color;
    input.color = color;
    cout << "Diameter: ";
    cin >> diameter;
    input.diameter = diameter;
    cout << "Icing? (y/n) ";
    cin >> icing;
    if (icing == 'y') {
        input.has_icing = true;
    }
    else {
        input.has_icing = false;
    }
    return input;
}

int main() {
    Cake input = makeCake ();
    printCakeInfo (input);
}
====
void printCakeInfo (Cake c) {
    if (c.name == "n/a") {
        if (c.has_icing) {
            cout << "This is a " << c.color << "," << c.diameter << " inch diameter cake with icing." << endl;
        }
        else {
            cout << "This is a " << c.color << "," << c.diameter << " inch diameter cake without icing." << endl;
        }
    }
    else {
        if (c.has_icing) {
            cout << "Happy birthday " << c.name << "! Your cake is " << c.color << ", has a " << c.diameter << " inch diameter, and comes with icing." << endl;
        }
        else {
            cout << "Happy birthday " << c.name << "! Your cake is " << c.color << ", has a " << c.diameter << " inch diameter, and comes without icing." << endl;
        }
    }
}

Write the editCake function, which prompts the user for a new name, color, diameter, and whether or not they want icing. The function modifies the original cake that is passed in as a parameter. Use the makeCake function in your implementation to avoid duplicate code!

#include <iostream>
using namespace std;

struct Cake {
    string name;
    string color;
    double diameter;
    bool has_icing;
};

void printCakeInfo (Cake c);
Cake makeCake ();

// Write your code for the editCake function here.

int main() {
    Cake original = { "Oops", "orange", 185, true };
    editCake (original);
    printCakeInfo (original);
}
====
 void printCakeInfo (Cake c) {
     if (c.name == "n/a") {
         if (c.has_icing) {
             cout << "This is a " << c.color << "," << c.diameter << " inch diameter cake with icing." << endl;
         }
         else {
             cout << "This is a " << c.color << "," << c.diameter << " inch diameter cake without icing." << endl;
         }
     }
     else {
         if (c.has_icing) {
             cout << "Happy birthday " << c.name << "! Your cake is " << c.color << ", has a " << c.diameter << " inch diameter, and comes with icing." << endl;
         }
         else {
             cout << "Happy birthday " << c.name << "! Your cake is " << c.color << ", has a " << c.diameter << " inch diameter, and comes without icing." << endl;
         }
     }
 }

Cake makeCake () {
     Cake input;
     string name, color;
     double diameter;
     char icing;
     cout << "Name: ";
     cin >> name;
     input.name = name;
     cout << "Color: ";
     cin >> color;
     input.color = color;
     cout << "Diameter: ";
     cin >> diameter;
     input.diameter = diameter;
     cout << "Icing? (y/n) ";
     cin >> icing;
     if (icing == 'y') {
         input.has_icing = true;
     }
     else {
         input.has_icing = false;
     }
     return input;
 }

Below is one way to implement the program. We call makeCake in editCake and then set the original cake equal to the new one.

#include <iostream>
using namespace std;

struct Cake {
    string name;
    string color;
    double diameter;
    bool has_icing;
};

void printCakeInfo (Cake c);
Cake makeCake ();

void editCake (Cake& c) {
    Cake newCake = makeCake ();
    c = newCake;
}

int main() {
    Cake original = { "Oops", "orange", 185, true };
    editCake (original);
    printCakeInfo (original);
}
====
 void printCakeInfo (Cake c) {
     if (c.name == "n/a") {
         if (c.has_icing) {
             cout << "This is a " << c.color << "," << c.diameter << " inch diameter cake with icing." << endl;
         }
         else {
             cout << "This is a " << c.color << "," << c.diameter << " inch diameter cake without icing." << endl;
         }
     }
     else {
         if (c.has_icing) {
             cout << "Happy birthday " << c.name << "! Your cake is " << c.color << ", has a " << c.diameter << " inch diameter, and comes with icing." << endl;
         }
         else {
             cout << "Happy birthday " << c.name << "! Your cake is " << c.color << ", has a " << c.diameter << " inch diameter, and comes without icing." << endl;
         }
     }
 }

Cake makeCake () {
     Cake input;
     string name, color;
     double diameter;
     char icing;
     cout << "Name: ";
     cin >> name;
     input.name = name;
     cout << "Color: ";
     cin >> color;
     input.color = color;
     cout << "Diameter: ";
     cin >> diameter;
     input.diameter = diameter;
     cout << "Icing? (y/n) ";
     cin >> icing;
     if (icing == 'y') {
         input.has_icing = true;
     }
     else {
         input.has_icing = false;
     }
     return input;
 }

Write the Pants structure, which has instance variables size and material.

Below is one way to implement the program. We declare the Pants struct and list the instance variables in order.

Write the printOutfit function, which prints out details of the outfit. The output below should be “Shirt: blue and L; Pants: S and denim; has hat”.

Below is one way to implement the program. We declare the Cake struct and list the instance variables in order.

9.15. Coding Practice¶