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Chapter 8: C Programming
ARRAYS
Arrays allow you to store a lot of related information in a convenient, organized fashion. An
array lets you use one line of code to create a series of variables. These variables share the
same basic name and are distinguished from one another by a numerical tag.
Example:
int count[10];
This means that an array named count has 10 members or “elements,” with each element
having its own value, starting with 0 and ending with 9. The first element is count[0], the
second element is count[1], and so on up to count[9]. The type int means that the actual
numerical value of each element is an integer.
Example:
count[2] = 7
count[4] = 131
count[9] = 26
SAMPLE PROGRAM:
This program calculates a one-hour average temperature. The array named "numbers" sets up
a series of variables from 0 to 60 to hold a value for input 1 for each minute in an hour. The
60 values are totalled, then averaged. The value of input 2 is then set to this average.
By using an array, the code becomes substantially more concise. The program is fir st listed,
then followed by a section by section explanation of how it works.
int numbers[60]; /* array: input 1 value for each minute */
int x; /* index to the array */
int total; /* total of the input 1 values */
int average; /* total/60 */
int oldminute; /* minute counter */
main()
{
if (oldminute != minutes)
{
oldminute = minutes;
numbers[minutes] = input(1);
total = 0;
for (x=0;x<60;x=x+1)
{
total = total + numbers[x];
}
average = total/60;
if ((total % 60) >= 30)
{
average = average + 1;
}
set_input(2,average);
}
}