Solution for Exercise 14-8

ex1408

#include <stdio.h>
#include <string.h>

int main()
{
    struct date
    {
        int month;
        int day;
        int year;
    };
    struct human
    {
        char name[45];
        struct date birthday;
    };
    struct human president;

    strcpy(president.name,"George Washington");
    president.birthday.month = 2;
    president.birthday.day = 22;
    president.birthday.year = 1732;

    printf("%s was born on %d/%d/%d\n",
            president.name,
            president.birthday.month,
            president.birthday.day,
            president.birthday.year);

    return(0);
}

Notes

* To reference a structure within a structure, you use two dots in the variable name, as shown in the solution for Exercise 14-8. president.brithday is a member in a structure, but that member is also a structure. Therefore you need to use two dots to get at the inside member's variables, president.birthday.day.

* Line 19 uses the strcpy() function to fill the president.name variable. Remember, you use strcpy() to copy string data, not the equal sign. Refer to Chapter 13 in the book.

* The date type of structure, such as the one shown above, is one of the most common to include within another structure.

* As discussed in the solution for Lesson 14-5, you can declare the structure's contents in the code, which may save some time. The method for declaring a structure within a structure involves a bonus set of curly brackets. This type of declaration for Exercise 14-8 might look like this:

    struct date
    {
        int month;
        int day;
        int year;
    };
    struct human
    {
        char name[45];
        struct date birthday;
    } president = {
        "George Washington", { 2, 22, 1732 }
    };

The birthday structure is included in the declaration in curly brackets. If you forget to include them, the compiler issues a warning. The code may still run, but I recommend keeping that internal structure's members in curly brackets as shown above.

Exercise ex1409 →