Chapter 11:
Arrays
Introduction to Programming with
C++
Fourth Edition
Objectives
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•
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Declare and initialize a one-dimensional array
Manipulate a one-dimensional array
Pass a one-dimensional array to a function
Use parallel one-dimensional arrays
Declare and initialize a two-dimensional array
Enter data into a two-dimensional array
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Using Arrays
• Simple or scalar variable - one that is
unrelated to any other variable in memory
• Array - a group of variables that have the same
name and data type and are related in some
way
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One-Dimensional Arrays
• Each variable in a one-dimensional array is
identified by a unique number called a subscript
• The subscript indicates the variable’s position in the
array
• First variable in a one-dimensional array is assigned
a subscript of 0 (zero), the second a subscript of 1
(one), and so on
• Elements – array variables
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Names of the Variables in a OneDimensional Array Named prices
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Declaring and Initializing OneDimensional Arrays
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The letters Array in Memory
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Storing Data in a One-Dimensional Array
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Manipulating One-Dimensional
Arrays
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Display the contents of an array
Access an array element using its subscript
Search the array
Calculate the average of the data stored in a
numeric array
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Manipulating One-Dimensional
Arrays (continued)
• Find the highest value stored in an array
• Update the array elements
• Sort the array elements
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Displaying the Contents of a OneDimensional Array
• displayMonths() function – demonstrates how
you can display the contents of the prices array
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displayMonths() Function
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Using the Subscript to Access an
Element in a One-Dimensional Array
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Searching a One-Dimensional Array
• Search through an array looking for elements
that are greater than a particular value
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Searching a One-Dimensional Array
(continued)
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Calculating the Average Amount Stored
in a One-Dimensional Numeric Array
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Determining the Highest Value
Stored in a One-Dimensional Array
• Search through an array looking for an element
whose value is larger than the largest value in
the array so far (high)
• When the loop is finished, high will be the largest
element in the array
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Determining the Highest Value Stored in
a One-Dimensional Array (continued)
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Updating the Values Stored in a OneDimensional Array
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Sorting the Data Stored in a OneDimensional Array
• Arranging data in a specific order is called
sorting
• Bubble sort algorithm: compare adjacent array
elements and interchange (swap) the ones that
are out of order
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Bubble Sort
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Passing a One-Dimensional Array to
a Function
• Arrays are passed by reference
– Address of the first element is passed
• Include the name of the array in the function call
• Do not include the address-of (&) operator
before the formal parameter’s name in the
function header or prototype
• Formal parameter in the header/prototype
should list data type, name, and empty square
brackets
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Passing a One-Dimensional Array to
a Function (continued)
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Using Parallel One-Dimensional
Arrays
• Parallel arrays – two or more arrays whose
elements are related by their position (subscript)
in the arrays
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Using Parallel One-Dimensional
Arrays (continued)
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Using Parallel One-Dimensional
Arrays (continued)
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Two-Dimensional Arrays
• Two-dimensional array resembles a table
• Variables or elements are identified by a unique
combination of two subscripts
• Subscripts specify the variable’s row and column
position in the array
• Initialize elements by entering a separate
initialValues section, enclosed in braces, for
each row in the array
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Two-Dimensional Arrays (continued)
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Two-Dimensional Arrays (continued)
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Two-Dimensional Array in Memory
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Storing Data in a Two-Dimensional
Array
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Storing Data in a Two-Dimensional
Array (continued)
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Summary
• Array - a group of variables that have the same
name and data type
• Subscript – a unique number assigned to each
array element in memory
• One-dimensional array - a column of variables
• Two-dimensional array - resembles a table in
that it has rows and columns
• You must declare all arrays and you should
initialize them
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Summary (continued)
• Various array manipulations:
– Displaying the contents of an array
– Accessing an array element using its
subscript
– Searching an array (“linear search”)
– Calculating the average of the data
– Finding the highest value stored in an array
– Updating the array elements
– Sorting the array elements
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Summary (continued)
• Arrays are passed to functions by reference
• Parallel arrays are two or more arrays whose
elements are related by their subscript (or
position) in the arrays
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