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How can I use switch to use a particular class function from an object with values determined by the user?

Shishykish (140)
Hello,

I have a task to make a simple fraction calculator using classes. I am having a particular issue where I cannot get my switch function to select a particular function in the object's class to perform the calculation. 

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#include <iostream>

using namespace std;

class fractions{

private:
    int A,B,C,D, SUM;

public:
    fractions(int = 1, int = 1, int = 1, int = 1, int = 0);

    void show_fractions();
    void sum_of_fractions(int, int, int, int, int);
    void diff_of_fractions(int, int, int,int);
    void product_of_fractions(int, int, int, int);
    void division_of_fractions (int, int, int, int);
};

fractions::fractions(int a, int b, int c, int d, int sum)
{
    A = a;
    B = b;
    C = c;
    D = d;
    SUM = sum;

    cout << " The constructor has created 2 fractions in the form a/b and c/d with the following values for a,b,c and d respectively" << endl;
    cout << A << "  " << B << " " << C << " "<< D << endl;
}

void fractions::show_fractions()
{
    cout    << " The fractions are "
            << A << " / " << B << " and " << C << " / " << D << endl;
}

void fractions::sum_of_fractions(int a, int b, int c, int d, int sum)
{
    int denominator;

    A = a;
    B = b;
    C = c;
    D = d;

    SUM = sum;

    denominator = (B * D);

    bool denominator_ok = false;

    while (denominator_ok)
    {
        try
        {
            if ((denominator == 0))
            {
                throw denominator;
            }
        }
        catch (int e)
        {
            cout << " You got a denominator of" << e << endl;
            cout << " This isn't a valid denominator,please re-enter B"<< endl;
            cin >> B;
            cout << " D isn't non-zero, please put in a non-zero integer" << endl;
            cin >> D;

            continue;
        }
        denominator_ok = false;
    }

    sum = (((A * D) + (C * B)) / (B * D));

cout << " The sum of 2 fractions in the form a/b and c/d with the following values for a,b,c and d respectively" << endl;
cout << A << "  " << B << " " << C << " "<< D << endl;
cout << " is " << sum;
}

void fractions::diff_of_fractions(int a, int b, int c, int d)
{

    int sum = 0;
    A = a;
    B = b;
    C = c;
    D = d;

    try
    {
        if (B == 0 || D == 0)
        {
            cout << " Re-enter a non-zero integer value for B" << endl;
                cin >> B;

            cout << " Re-enter a non-zero integer value for D" << endl;
                cin >> D;
        }
        else
        {
            sum = ((A * D) - (C * B)) / (B * D);

            cout << " The difference of 2 fractions in the form a/b and c/d with the following values for a,b,c and d respectively" << endl;
            cout << A << "  " << B << " " << C << " "<< D << endl;
            cout << " is " << sum;
        }
    }
    catch (int e)
    {
        cout << " A denominator of " << e << " is invalid"<<endl;
    }
}

void fractions::product_of_fractions(int a, int b, int c, int d)
{
    int sum = 0;
    A = a;
    B = b;
    C = c;
    D = d;

    try
    {
        if (B == 0 || D == 0)
        {
            cout << " Re-enter a non-zero integer value for B" << endl;
                cin >> B;

            cout << " Re-enter a non-zero integer value for D" << endl;
                cin >> D;
        }
        else
        {
            sum = (A * C) / (B * D);

            cout << " The product of 2 fractions in the form a/b and c/d with the following values for a,b,c and d respectively" << endl;
            cout << A << "  " << B << " " << C << " "<< D << endl;
            cout << " is " << sum;
        }
    }
    catch (int e)
    {
        cout << " A denominator of " << e << " is invalid"<<endl;
    }
}

void fractions::division_of_fractions(int a, int b, int c, int d)
{
    int sum = 0;
    A = a;
    B = b;
    C = c;
    D = d;

    try
    {
        if (B == 0 || C == 0)
        {
            cout << " Re-enter a non-zero integer value for B" << endl;
                cin >> B;

            cout << " Re-enter a non-zero integer value for D" << endl;
                cin >> D;
        }
        else
        {
            sum = (A * D) / (B * C);

            cout << " The product of 2 fractions in the form a/b and c/d with the following values for a,b,c and d respectively" << endl;
            cout << A << "  " << B << " " << C << " "<< D << endl;
            cout << " is " << sum;
        }
    }
    catch (int e)
    {
        cout << " A denominator of " << e << " is invalid"<<endl;
    }
}

int main()
{
    fractions A;

    char option;
    int AA,BB,CC,DD;

    cout << " What would you like the fraction calculator to do ?" << endl;

    switch(option)
    {
        case'+':
            {
                A.sum_of_fractions(AA, BB, CC, DD, 0);
            }
            break;

        case'-':
            {
                A.diff_of_fractions(AA, BB, CC, DD);
            }
            break;

        case'*':
            {
                A.product_of_fractions(AA,BB,CC,DD);
            }
            break;

        case'/':
            {
                A.division_of_fractions(AA, BB, CC, DD);
            }
            break;

        default:
            cout<<"Wrong information entered. "<<"\nTry again. ";
    }

    cout << "Enter the fractions you'd like to add in the form a / b and c / d" << endl;

    cout << " The constructor has created 2 fractions in the form a/b and c/d with the following values for a,b,c and d respectively" << endl;
    cout << AA << "  " << BB << " " << CC << " "<< DD << endl;

    return 0;
}
joe864864 (249)
Most likely you are getting an error of variables are not initialized because option hits the switch statement and option doesn't have a value and if it did AA,BB,CC,DD don't have values either. You need to initialize them or get user input for them.
Shishykish (140)
Dear Joe,

Doh! Thanks for spotting that! I feel like a right dufus now for not putting in the cin >> command! I'll give that a go.
Shishykish (140)
Hello Joe,

I managed to get it working and just simplified it to just use the different member functions of the class. Works nicely. 

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#include <iostream>

using namespace std;

class fractions{


private:
    int A,B,C,D, SUM;

public:
    fractions(int = 1, int = 1, int = 1, int = 1, int = 0);

    void show_fractions(float,float,float,float);
    float sum_of_fractions(float,float,float,float);
    float diff_of_fractions(float,float,float,float);
    float product_of_fractions(float,float,float,float);
    float division_of_fractions (float,float,float,float);
};

fractions::fractions(int a, int b, int c, int d, int sum)
{
    A = a;
    B = b;
    C = c;
    D = d;
    SUM = sum;

    cout << " The constructor has created 2 fractions in the form a/b and c/d with the following values for a,b,c and d respectively" << endl;
    cout << A << "  " << B << " " << C << " "<< D << endl;
}

void fractions::show_fractions(float A,float B,float C, float D)
{
    cout    << " The fractions are "
            << A << " / " << B << " and " << C << " / " << D << endl;
}

float fractions::sum_of_fractions(float A,float B,float C, float D)
{
    float denominator = 0;
    float sum = 0;

    cout << " The  2 fractions in the form a/b and c/d with the following values for a,b,c and d respectively" << endl;
    cout << A << "/" << B << " and " << C << "/"<< D << endl;

        denominator = (B * D);

    cout << " The denominator of " << B << " x " << D << endl;

    bool denominator_not_ok = true;

    while (denominator_not_ok)
    {
        try
        {
            if ((denominator == 0))
            {
                cout << "denominator is a zero value" << endl;
                throw denominator;
            }
        }
        catch (int e)
        {
            cout << " What are the values of A?" << endl;
            cin >> A;

            cout << " What are the values of B?" << endl;
            cin >> B;

            cout << " What are the values of B?" << endl;
            cin >> C;

            cout << "What is the value of D?"<< endl;
            cin >> D;
        }
        denominator_not_ok = false;
    }

    sum = (((A * D) + (C * B)) / (B * D));

cout << " The sum of 2 fractions in the form a/b and c/d with the following values for a,b,c and d respectively" << "   ";
cout << A << "/" << B << " and " << C << "/"<< D << endl;
cout << " is " << sum << endl;

return sum;

}

float fractions::diff_of_fractions(float A,float B,float C, float D)
{

    float denominator = 0;
    float sum = 0;

    cout << " The  2 fractions in the form a/b and c/d with the following values for a,b,c and d respectively" << endl;
    cout << A << "/" << B << " and " << C << "/"<< D << endl;

    denominator = (B * D);

    cout << " The denominator of (" << B << " x " << D << ")"<< endl;

    bool denominator_not_ok = true;

    while (denominator_not_ok)
    {
        try
        {
            if ((denominator == 0))
            {
                cout << "denominator is a zero value" << endl;
                throw denominator;
            }
        }
        catch (int e)
        {
            cout << " What are the values of A?" << endl;
            cin >> A;

            cout << " What are the values of B?" << endl;
            cin >> B;

            cout << " What are the values of B?" << endl;
            cin >> C;

            cout << "What is the value of D?"<< endl;
            cin >> D;
        }
        denominator_not_ok = false;
    }

    sum = (((A * D) - (C * B)) / (B * D));

cout << " The difference between 2 fractions in the form a/b and c/d with the following values for a,b,c and d respectively" << "   ";
cout << A << "/" << B << " - " << C << "/"<< D << " = " << sum << endl;

return sum;
}

float fractions::product_of_fractions(float A,float B,float C, float D)
{
    float denominator = 0;
    float sum = 0;

    denominator = (B * D);

    cout << " The denominator is (" << B << " x " << D << ")"<< endl;

    bool denominator_not_ok = true;

    while (denominator_not_ok)
    {
        try
        {
            if ((denominator == 0))
            {
                cout << "denominator is a zero value" << endl;
                throw denominator;
            }
        }
        catch (int e)
        {
            cout << " What are the values of A?" << endl;
            cin >> A;

            cout << " What are the values of B?" << endl;
            cin >> B;

            cout << " What are the values of B?" << endl;
            cin >> C;

            cout << "What is the value of D?"<< endl;
            cin >> D;
        }
        denominator_not_ok = false;
    }

    sum = ((A * C) / (B * D));

cout << " The difference between 2 fractions in the form a/b and c/d with the following values for a,b,c and d respectively" << "   ";
cout << A << "/" << B << " x " << C << "/"<< D << " = " << sum << endl;

return sum;
}

float fractions::division_of_fractions(float A,float B,float C, float D)
{
    float denominator = 0;
    float sum = 0;

    cout << " The  2 fractions in the form a/b and c/d with the following values for a,b,c and d respectively" << endl;
    cout << A << "/" << B << " and " << C << "/"<< D << endl;

    denominator = (B * C);

    cout << " The denominator of (" << B << " x " << C << ")"<< endl;

    bool denominator_not_ok = true;

    while (denominator_not_ok)
    {
        try
        {
            if ((denominator == 0))
            {
                cout << "denominator is a zero value" << endl;
                throw denominator;
            }
        }
        catch (int e)
        {
            cout << " What are the values of A?" << endl;
            cin >> A;

            cout << " What are the values of B?" << endl;
            cin >> B;

            cout << " What are the values of B?" << endl;
            cin >> C;

            cout << "What is the value of D?"<< endl;
            cin >> D;
        }
        denominator_not_ok = false;
    }

    sum = ((A * D) / (B * C));

cout << " The difference between 2 fractions in the form a/b and c/d with the following values for a,b,c and d respectively" << "   ";
cout << A << "/" << B << " / " << C << "/"<< D << " = " << sum << endl;

return sum;
}

int main()
{
    float A,B,C,D;

    cout << "To calculate the sum, difference, product and division of 2 fractions in the form A / B and C / D you need to enter some numbers" << endl;

    cout << "What are the values of A?" << endl;
    cin >> A;

    cout << "What are the values of B?" << endl;
    cin >> B;

    cout << "What are the values of B?" << endl;
    cin >> C;

    cout << "What is the value of D?"<< endl;
    cin >> D;

    cout << "The  2 fractions in the form a/b and c/d with the following values for a,b,c and d respectively" << endl;
    cout << A << "/" << B << " and " << C << "/"<< D << endl;

    fractions AA;

    //A.show_fractions(A,B,C,D);
    AA.sum_of_fractions(A,B,C,D);
    AA.diff_of_fractions(A,B,C,D);
    AA.product_of_fractions(A,B,C,D);
    AA.division_of_fractions(A,B,C,D);

    return 0;

    /*cout << " What would you like the fraction calculator to do ?" << endl;

    cin >> option;


    switch(option)
    {
        case'+':
            {
                A.sum_of_fractions(AA, BB, CC, DD, 0);
            }
            break;

        case'-':
            {
                A.diff_of_fractions(AA, BB, CC, DD);
            }
            break;

        case'*':
            {
                A.product_of_fractions(AA,BB,CC,DD);
            }
            break;

        case'/':
            {
                A.division_of_fractions(AA, BB, CC, DD);
            }
            break;

        default:
            cout<<"Wrong information entered. "<<"\nTry again. ";
    }
*/
}
Shishykish (140)
Unfortunately, If I enter a zero value to test the try-catch loop, my program crashes. Not sure where I am going wrong.

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#include <iostream>

using namespace std;

class fractions{


private:
    int A,B,C,D, SUM;

public:
    fractions(int = 1, int = 1, int = 1, int = 1, int = 0);

    void show_fractions(float,float,float,float);
    float sum_of_fractions(float,float,float,float);
    float diff_of_fractions(float,float,float,float);
    float product_of_fractions(float,float,float,float);
    float division_of_fractions (float,float,float,float);
};

fractions::fractions(int a, int b, int c, int d, int sum)
{
    A = a;
    B = b;
    C = c;
    D = d;
    SUM = sum;

    cout << " The constructor has created 2 fractions in the form a/b and c/d with the following values for a,b,c and d respectively" << endl;
    cout << A << "  " << B << " " << C << " "<< D << endl;
}

void fractions::show_fractions(float A,float B,float C, float D)
{
    cout    << " The fractions are "
            << A << " / " << B << " and " << C << " / " << D << endl;
}

float fractions::sum_of_fractions(float A,float B,float C, float D)
{
    float denominator = 0;
    float sum = 0;

    cout << " The  2 fractions in the form a/b and c/d with the following values for a,b,c and d respectively" << endl;
    cout << A << "/" << B << " and " << C << "/"<< D << endl;

        denominator = (B * D);

    cout << " The denominator of " << B << " x " << D << endl;

    bool denominator_not_ok = true;

    while (denominator_not_ok)
    {
        try
        {
            if ((denominator == 0))
            {
                cout << "denominator is a zero value" << endl;
                throw denominator;
            }
        }
        catch (int e)
        {
            cout << " What are the values of A?" << endl;
            cin >> A;

            cout << " What are the values of B?" << endl;
            cin >> B;

            cout << " What are the values of B?" << endl;
            cin >> C;

            cout << "What is the value of D?"<< endl;
            cin >> D;
        }
        denominator_not_ok = false;
    }

    sum = (((A * D) + (C * B)) / (B * D));

cout << " The sum of 2 fractions in the form a/b and c/d with the following values for a,b,c and d respectively" << "   ";
cout << A << "/" << B << " and " << C << "/"<< D << endl;
cout << " is " << sum << endl;

return sum;

}

float fractions::diff_of_fractions(float A,float B,float C, float D)
{

    float denominator = 0;
    float sum = 0;

    cout << " The  2 fractions in the form a/b and c/d with the following values for a,b,c and d respectively" << endl;
    cout << A << "/" << B << " and " << C << "/"<< D << endl;

    denominator = (B * D);

    cout << " The denominator of (" << B << " x " << D << ")"<< endl;

    bool denominator_not_ok = true;

    while (denominator_not_ok)
    {
        try
        {
            if ((denominator == 0))
            {
                cout << "denominator is a zero value" << endl;
                throw denominator;
            }
        }
        catch (int e)
        {
            cout << " What are the values of A?" << endl;
            cin >> A;

            cout << " What are the values of B?" << endl;
            cin >> B;

            cout << " What are the values of B?" << endl;
            cin >> C;

            cout << "What is the value of D?"<< endl;
            cin >> D;
        }
        denominator_not_ok = false;
    }

    sum = (((A * D) - (C * B)) / (B * D));

cout << " The difference between 2 fractions in the form a/b and c/d with the following values for a,b,c and d respectively" << "   ";
cout << A << "/" << B << " - " << C << "/"<< D << " = " << sum << endl;

return sum;
}

float fractions::product_of_fractions(float A,float B,float C, float D)
{
    float denominator = 0;
    float sum = 0;

    denominator = (B * D);

    cout << " The denominator is (" << B << " x " << D << ")"<< endl;

    bool denominator_not_ok = true;

    while (denominator_not_ok)
    {
        try
        {
            if ((denominator == 0))
            {
                cout << "denominator is a zero value" << endl;
                throw denominator;
            }
        }
        catch (int e)
        {
            cout << " What are the values of A?" << endl;
            cin >> A;

            cout << " What are the values of B?" << endl;
            cin >> B;

            cout << " What are the values of B?" << endl;
            cin >> C;

            cout << "What is the value of D?"<< endl;
            cin >> D;
        }
        denominator_not_ok = false;
    }

    sum = ((A * C) / (B * D));

cout << " The difference between 2 fractions in the form a/b and c/d with the following values for a,b,c and d respectively" << "   ";
cout << A << "/" << B << " x " << C << "/"<< D << " = " << sum << endl;

return sum;
}

float fractions::division_of_fractions(float A,float B,float C, float D)
{
    float denominator = 0;
    float sum = 0;

    cout << " The  2 fractions in the form a/b and c/d with the following values for a,b,c and d respectively" << endl;
    cout << A << "/" << B << " and " << C << "/"<< D << endl;

    denominator = (B * C);

    cout << " The denominator of (" << B << " x " << C << ")"<< endl;

    bool denominator_not_ok = true;

    while (denominator_not_ok)
    {
        try
        {
            if ((denominator == 0))
            {
                cout << "denominator is a zero value" << endl;
                throw denominator;
            }
        }
        catch (int e)
        {
            cout << " What are the values of A?" << endl;
            cin >> A;

            cout << " What are the values of B?" << endl;
            cin >> B;

            cout << " What are the values of B?" << endl;
            cin >> C;

            cout << "What is the value of D?"<< endl;
            cin >> D;
        }
        denominator_not_ok = false;
    }

    sum = ((A * D) / (B * C));

cout << " The difference between 2 fractions in the form a/b and c/d with the following values for a,b,c and d respectively" << "   ";
cout << A << "/" << B << " / " << C << "/"<< D << " = " << sum << endl;

return sum;
}

int main()
{
    float A,B,C,D;

    cout << "To calculate the sum, difference, product and division of 2 fractions in the form A / B and C / D you need to enter some numbers" << endl;

    cout << "What are the values of A?" << endl;
    cin >> A;

    cout << "What are the values of B?" << endl;
    cin >> B;

    cout << "What are the values of B?" << endl;
    cin >> C;

    cout << "What is the value of D?"<< endl;
    cin >> D;

    cout << "The  2 fractions in the form a/b and c/d with the following values for a,b,c and d respectively" << endl;
    cout << A << "/" << B << " and " << C << "/"<< D << endl;

    fractions AA;

    //A.show_fractions(A,B,C,D);
    AA.sum_of_fractions(A,B,C,D);
    AA.diff_of_fractions(A,B,C,D);
    AA.product_of_fractions(A,B,C,D);
    AA.division_of_fractions(A,B,C,D);

    return 0;
}
boost lexical cast (395)
Shishykish wrote:
Unfortunately, If I enter a zero value to test the try-catch loop, my program crashes. Not sure where I am going wrong.

Why did you mark your question as solved then? If you did it because the code worked before, then mark as unsolved.
Shishykish (140)
Hello,

I am sorry, I didn't notice that. I clicked on it twice by accident! I've since specified the problem in another post.

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