Dale Roberts, Lecturer

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Department of Computer and Information
Science,School of Science, IUPUI
CSCI 230
Arrays Multidimensional Arrays

• Dale Roberts, Lecturer
• IUPUI
• droberts_at_cs.iupui.edu

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Multiple-Dimensional Arrays

• Multiple subscripted arrays
• Arrays require at least two subscripts to
  identify a particular element
• ANSI C standard allows at least 12 array
  subscripts
• 2D Arrays
• Tables with rows and columns (m by n array)
• Like matrices specify row, then column

A00 (2 subscripts) 2D array
(matrix) 2-dimensional vector
A scalar
A0 1D array 1-Dimensional vector
A common error is to use math matrix notation
a(1,2)
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Multiple-Subscripted Arrays

• Initialization
• int b22 1, 2 , 3, 4
• int c32 1, 2 , 3, 4 , 5, 6
• Initializers grouped by row in braces
• If not enough, unspecified elements set to zero
• int b 2 2 1 , 3, 4
• Referencing elements
• Specify row, then column
• printf( "d", b 0 1 )

1 2 3 4
Actual storage in the memory - rows by rows
-row-major
1 2 3 4 5 6
5 6

 
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const indicates that the function does not modify
the array.

• Initialize variables
• Define functions to take double scripted arrays
• Initialize studentgrades
• Call functions minimum, maximum, and average

Each row is a particular student, each column is
the grades on the exam. Proper naming of the
defined constants is important to convey meaning.
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Why is it important to initialize lowGrade to the
highest possible grade, and highGrade to the
lowest possible grade?
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• Define function

The array is 0 1 2
3 studentGrades0 77 68 86 73
studentGrades1 96 87 89 78
studentGrades2 70 90 86 81 Lowest
grade 68 Highest grade 96 The average grade for
student 0 is 76.00 The average grade for student
1 is 87.50 The average grade for student 2 is
81.75
Program Output