COMP 102 Programming Fundamentals I

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COMP 102Programming Fundamentals I

• Presented by Timture Choi

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2-D Array

• E.g.
• // declare a 2-D array of 30 uninitialized
  integers
• int table310
• 3 rows
• 10 columns

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2-D Array

• Accessing 2-D array
• Syntax
• arrayrowcolumn
• E.g.
• table12 5
• x table12

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2-D Array Initialization

• Two methods to initialize a 2-D array
• int table36 1,2,3,4,5,6,7,8,9,10,11,12,13,1
  4,15,16,17,18
• int table36
• 1,2,3,4,5,6,
• 7,8,9,10,11,12,
• 13,14,15,16,17,18

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2-D Array Inputting Values

• Use two for loops to access/process all the
  elements of a 2-D array
• E.g.

int total_row 3, total_col 6 for (int row0
rowlttotal_row row) for (int col 0
collttotal_col col) // assign value to an
element of array tablerowcol
rowcol // assign value of an element
to a variable temp tablerowcol
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Mathematical Functions

• include ltmathgt
• double log(double x)
• Natural logarithm
• double log10(double x)
• Base 10 logarithm
• double exp(double x)
• e to the power x
• double pow(double x, double y)
• x to the power y
• double sqrt(double x)
• Square root of x
• double sin(double x)
• double cos(double x)
• double tan(double x)
• In radian argument

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Mathematical Functions

• double ceil(double x)
• Smallest integer not less than x
• E.g.
• ceil(1.1) gt 2
• ceil(-1.9) gt -1
• double floor(double x)
• Largest integer not greater than x
• E.g.
• floor(1.9) gt 1
• floor(-1.1) gt -2
• ltmath.hgt will not provide the round-off function

double d int i int i (int) (dgt0 ? d0.5
d-0.5)
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Passing Arrays as Parameters

• 1-D
• int func(int arraysize, int size)
• int func(const int arraysize, int size)
• 2-D
• int func(int arrayrowcol, int row, int col)
• int func(const int arrayrowcol, int row, int
  col)
• The in the formal parameter specification
• Indicates that the variable is an array
• It is a good practice to pass the dimension of
  the array as another parameter
• Arrays are always passed by reference
• If the function must not change any element of
  the array
• const should be used

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SUMMARY

• By the end of this lab, you should be able to
• Declare and manipulate
• 2-D arrays
• Use mathematical functions provide by
• ltmathgt
• Pass an array to a function
• Normally
• With const keyword