C++ Primer Plus

    cout << pa->name << endl;

    for (int i = 0; i < 3; i++)

        cout  << pa->credit_ratings[i] <<  endl;

}

13.

typedef void (*p_f1)(applicant *);

p_f1 p1 = f1;

typedef const char * (*p_f2)(const applicant *, const applicant *);

p_f2 p2 = f2;

p_f1 ap[5];

p_f2 (*pa)[10];

Answers to Chapter Review for Chapter 8

1. Short, nonrecursive functions that can fit in one line of code are good candidates for inline status.

2.

a. void song(const char * name, int times = 1);

b. None. Only prototypes contain the default value information.

c. Yes, provided that you retain the default value for times:

void song(char * name = "O, My Papa", int times = 1);

3. You can use either the string ″\″″ or the character ′″′ to print a quotation mark. The following functions show both methods:

#include

void iquote(int n)

{

    cout << "\"" << n << "\"";

}

void iquote(double x)

{

    cout << '"' << x << '"';

}

void iquote(const char * str)

{

    cout << "\"" << str << "\"";

}

4.

a. This function shouldn’t alter the structure members, so use the const qualifier:

void show_box(const box & container)

{

    cout << "Made by " << container. maker << endl;

    cout << "Height = " << container.height << endl;

    cout << "Width = " << container.width << endl;

    cout << "Length = " << container.length << endl;

    cout << "Volume = " << container.volume << endl;

}

b.

void set_volume(box & crate)

{

    crate.volume = crate.height * crate.width * crate.length;

}

5. First, change the prototypes to the following:

// function to modify array object

void fill(std::array & pa);

// function that uses array object without modifying it

void show(const std::array & da);

Note that show() should use const to protect the object from being modified. Next, within main(), change the fill() call to this:

fill(expenses);

There’s no change to the show() call.

Next, the new fill() should look like this:

void fill(std::array & pa)  // changed

{

    using namespace std;

    for (int i = 0; i < Seasons; i++)

    {

        cout << "Enter " << Snames[i] << " expenses: ";

        cin >> pa[i];     // changed

    }

}

Note that (*pa)[i] gets changed to the simpler pa[i].

Finally, the only change to show() is to the function header:

void show(std::array & da)

6.

a. This can be done by using a default value for the second argument:

double mass(double d, double v = 1.0);

It can also be done by using function overloading:

double mass(double d, double v);

double mass(double d);

b. You can’t use a default for the repeat value because you have to provide default values from right to left. You can use overloading:

void repeat(int times, const char * str);

void repeat(const char * str);

c. You can use function overloading:

int average(int a, int b);

double average(double x, double y);

d. You can’t do this because both versions would have the same signature.

7.

template

T max(T t1, T t2)  // or T max(const T & t1, const T & t2)

{

    return t1 > t2? t1 : t2;

}

8.

template<> box max(box b1, box b2)

{

    return b1.volume > b2.volume? b1 : b2;

}

9. v1 is type float, v2 is type float &, v3 is type float &, v4 is type int, and v5 is type double. The literal 2.0 is type double, so the product 2.0 * m is double.

Answers to Chapter Review for Chapter 9

1.

a. homer is automatically an automatic variable.

b. secret should be defined as an external variable in one file and declared using extern in the second file.

c. topsecret could be defined as a static variable with internal linkage by prefacing the external definition with the keyword static. Or it could be defined in an unnamed namespace.

d. beencalled should be defined as a local static variable by prefacing a declaration in the function with the keyword static.

2. A using declaration makes available a single name from a namespace, and it has the scope corresponding to the declarative region in which the using declaration occurs. A using directive makes available all the names in a namespace. When you use a using directive, it is as if you have declared the names in the smallest declarative region containing both the using declaration and the namespace itself.

3.

#include

int main()

{

    double x;

    std::cout << "Enter value: ";

    while (! (std::cin >> x) )

    {

        std::cout << "Bad input. Please enter a number: ";

        std::cin.clear();

       while (std::cin.get() != '\n')

           continue;

    }

    std::cout << "Value = " << x << std::endl;

    return 0;

}

4. Here is the revised code:

#include

int main()

{

    using std::cin;

    using std::cout;

    using std::endl;

    double x;

    cout << "Enter value: ";

    while (! (cin >> x) )

    {

        cout << "Bad input. Please enter a number: ";

        cin.clear();

       while (cin.get() != '\n')

           continue;

    }

    cout << "Value = " << x << endl;

    return 0;

}

5. You could have separate static function definitions in each file. Or each file could define the appropriate average() function in an unnamed namespace.

6.

10

4

0

Other: 10, 1

another(): 10, -4

7.

1

4, 1, 2

2

2

4, 1, 2

2

Answers to Chapter Review for Chapter 10