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. 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

10. 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

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

12. 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

13. 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

14. 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

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

16. 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

17. 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

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

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

20. 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

21. 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

22. 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

23. Summary (continued) • Parallel arrays are two or more arrays whose elements are related by their subscript in the arrays • To create a two-dimensional array specify the number of rows and columns • Each element is identified by two subscripts • First subscript represents the element’s row location • Second subscript represents its column location • Use two loops to access every element in a two-dimensional array An Introduction to Programming with C++, Fifth Edition

24. Application Lesson: Using Arrays in a C++ Program • Lab 11.1: Stop and Analyze • Lab 11.2 • Program should either display the monthly rainfall amounts on the screen or calculate and display the total rainfall amount • Lab 11.3 • Modified program will use a value-returning function, calcTotal(), to calculate the total rainfall amount • Lab 11.4: Desk-Check Lab • Lab 11.5: Debugging Lab An Introduction to Programming with C++, Fifth Edition