An Introduction to Programming with C++ Fifth Edition

1. An Introduction to Programming with C++Fifth Edition Chapter 11 Arrays

2. Objectives • Declare and initialize a one-dimensional array • Manipulate a one-dimensional array • Explain the bubble sort algorithm • Pass a one-dimensional array to a function • Use parallel one-dimensional arrays An Introduction to Programming with C++, Fifth Edition

3. Objectives (continued) • Declare and initialize a two-dimensional array • Enter data into a two-dimensional array • Search a two-dimensional array • Utilize a one-dimensional array in a .NET C++ program An Introduction to Programming with C++, Fifth Edition

4. Concept Lesson • Using Arrays • One-Dimensional Arrays • Storing Data in a One-Dimensional Array • Manipulating One-Dimensional Arrays • Passing a One-Dimensional Array to a Function An Introduction to Programming with C++, Fifth Edition

5. Concept Lesson (continued) • Using Parallel One-Dimensional Arrays • Two-Dimensional Arrays • Storing Data in a Two-Dimensional Array • Searching a Two-Dimensional Array An Introduction to Programming with C++, Fifth Edition

6. Using Arrays • Simple variable is unrelated to other variables in computer’s internal memory • Also called a scalar variable • Array is a group of variables • Same name and data type • Variables are related in some way • Most commonly used • One-dimensional • Three-dimensional An Introduction to Programming with C++, Fifth Edition

7. Element One-Dimensional Arrays • Visualize a one-dimensional array as a column of variables • Subscript (or index) identifies each variable • Indicates the variable’s position in the array • Subscript of first variable is 0 • Begin by populating the array so it does not contain garbage An Introduction to Programming with C++, Fifth Edition

8. One-Dimensional Arrays (continued) An Introduction to Programming with C++, Fifth Edition

9. Storing Data in a One-Dimensional Array • Can use an assignment statement to enter data into an array • See Figure 11-3 • Can use >> and getline() • See Figure 11-4 An Introduction to Programming with C++, Fifth Edition

10. Storing Data in a One-Dimensional Array (continued) An Introduction to Programming with C++, Fifth Edition

11. Storing Data in a One-Dimensional Array (continued) An Introduction to Programming with C++, Fifth Edition

12. Storing Data in a One-Dimensional Array (continued) An Introduction to Programming with C++, Fifth Edition

13. Manipulating One-Dimensional Arrays • Common array manipulation functions • Display the contents of an array • Access an array element using its subscript • Search an array • Calculate the average of the data stored in an array • Find the highest value stored in an array • Update the array elements • Sort the array elements using bubble sort An Introduction to Programming with C++, Fifth Edition

14. Displaying the Contents of aOne-Dimensional Array • Function may need simply to display the contents of an array An Introduction to Programming with C++, Fifth Edition

15. Displaying the Contents of aOne-Dimensional Array (continued) An Introduction to Programming with C++, Fifth Edition

16. Using the Subscript to Access an Element in a One-Dimensional Array • Before accessing element, verify if subscript is valid An Introduction to Programming with C++, Fifth Edition

17. Searching a One-Dimensional Array • Sales manager wants to determine the number of salespeople selling above a specific amount • Function searches the sales array • Array contains amount sold by each salesperson • Look for values greater than the amount provided by sales manager An Introduction to Programming with C++, Fifth Edition

18. Searching a One-Dimensional Array (continued) An Introduction to Programming with C++, Fifth Edition

19. Calculating the Average Amount Stored in a One-Dimensional Numeric Array • Prof. Jeremiah wants to calculate and display average test score earned by students on final • Function adds test scores that are stored in array • Then, divide sum by number of elements An Introduction to Programming with C++, Fifth Edition

20. Calculating the Average Amount Stored in a One-Dimensional Numeric Array (continued) An Introduction to Programming with C++, Fifth Edition

21. Determining the Highest Value Stored in a One-Dimensional Array • Sharon Johnson keeps track of the amount of money she earns each week • Function displays highest amount earned in a week • Stores pay amounts in a one-dimensional array An Introduction to Programming with C++, Fifth Edition

22. Determining the Highest Value Stored in a One-Dimensional Array (continued) An Introduction to Programming with C++, Fifth Edition

23. Updating the Values Stored in aOne-Dimensional Array • Sales manager at Jillian Company wants a function that increases the price of each item company sells • Function stores prices in a one-dimensional array • Then, increase value stored in each element • Also, display each item’s new price on screen An Introduction to Programming with C++, Fifth Edition

24. Updating the Values Stored in aOne-Dimensional Array (continued) An Introduction to Programming with C++, Fifth Edition

25. Sorting the Values Stored in aOne-Dimensional Array • Arranging data in a specific order is called sorting • Ascending or descending order • Bubble sort isquick and easy (for small arrays) • Adjacent elements that are out of order are swapped An Introduction to Programming with C++, Fifth Edition

26. Sorting the Values Stored in aOne-Dimensional Array (continued) An Introduction to Programming with C++, Fifth Edition

27. Sorting the Values Stored in aOne-Dimensional Array (continued) An Introduction to Programming with C++, Fifth Edition

28. Sorting the Values Stored in aOne-Dimensional Array (continued) An Introduction to Programming with C++, Fifth Edition

29. Sorting the Values Stored in aOne-Dimensional Array (continued) An Introduction to Programming with C++, Fifth Edition

30. Sorting the Values Stored in aOne-Dimensional Array (continued) An Introduction to Programming with C++, Fifth Edition

31. Sorting the Values Stored in aOne-Dimensional Array (continued) An Introduction to Programming with C++, Fifth Edition

32. Sorting the Values Stored in aOne-Dimensional Array (continued) An Introduction to Programming with C++, Fifth Edition

33. Passing a One-Dimensional Array to a Function • By default, scalar variables are passed by value • To pass by reference,use address-of (&) operator • Arrays in C++ are passed by reference • More efficient • Address of first element is passed to function • Address-of operator is not used An Introduction to Programming with C++, Fifth Edition

34. Passing a One-Dimensional Array to a Function (continued) An Introduction to Programming with C++, Fifth Edition

35. Using Parallel One-Dimensional Arrays • Takoda Tapahe wants a program that displays the price of the item whose product ID she enters An Introduction to Programming with C++, Fifth Edition

36. Using Parallel One-Dimensional Arrays (continued) • Parallel arrays are two or more arrays whose elements are related by their position in the arrays • Related by their subscript An Introduction to Programming with C++, Fifth Edition

37. Using Parallel One-Dimensional Arrays (continued) An Introduction to Programming with C++, Fifth Edition

38. Using Parallel One-Dimensional Arrays (continued) An Introduction to Programming with C++, Fifth Edition

39. Two-Dimensional Arrays • Two-dimensional array resembles a table • Elements are in rows and columns • Each element is identified by two subscripts • Subscripts specify the variable’s row and column position in the array An Introduction to Programming with C++, Fifth Edition

40. Two-Dimensional Arrays (continued) An Introduction to Programming with C++, Fifth Edition

41. Two-Dimensional Arrays (continued) An Introduction to Programming with C++, Fifth Edition

42. Storing Data in a Two-Dimensional Array • You can use an assignment statement to enter data into a two-dimensional array • Or use >> and getline() • Use two loops to access every element in a two-dimensional array • One loop tracks row subscript • Other loop tracks column subscript An Introduction to Programming with C++, Fifth Edition

43. Storing Data in a Two-Dimensional Array (continued) An Introduction to Programming with C++, Fifth Edition

44. Storing Data in a Two-Dimensional Array (continued) An Introduction to Programming with C++, Fifth Edition

45. Storing Data in a Two-Dimensional Array (continued) An Introduction to Programming with C++, Fifth Edition

46. Searching a Two-Dimensional Array • Two one-dimensional (parallel) arrays can be replaced with one two-dimensional array An Introduction to Programming with C++, Fifth Edition

47. Searching a Two-Dimensional Array (continued) An Introduction to Programming with C++, Fifth Edition

48. Searching a Two-Dimensional Array (continued) An Introduction to Programming with C++, Fifth Edition

49. Searching a Two-Dimensional Array (continued) An Introduction to Programming with C++, Fifth Edition

50. Summary • An array is a group of variables that have the same name and data type and are related in some way • One-dimensional • Visualize as a column of variables • Two-dimensional • Visualize as a table • You must declare an array before you can use it • Each elements in a one-dimensional array is assigned a subscript • First element has subscript 0 An Introduction to Programming with C++, Fifth Edition