Name:
Sec: 06/22/2006
Programming Assignment #3
Using 2-Dimensional Arrays
Two dimensional arrays can be thought of as tables of data. A familiar example of
a table of data is the spreadsheet, such as Microsoft Excel, where you arrange data
into rows and columns. To declare a 2-Dimensional array in C, we do the
following:
const int NUM_ROWS = 8;
const int NUM_COLUMNS = 5;
int table[NUM_ROWS][NUM_COLUMNS];
The above, as you can probably guess, creates an array called table, that can
hold/represent a table with 8 rows and 5 columns. Of course, by changing the
named constants NUM_ROWS and/or NUM_COLUMNS, you can change the
size of the table that is being created and represented. However, unlike a
spreadsheet, 2-dimensional arrays in C must always start at index 0 for both the
row index and the column index. By convention, the first index is used to index
the row number, and the second index the column number. This convention is
somewhat arbitrary, they could be reversed, but in most of mathematics and
programming you will see people using this ordering when working with 2-
dimensional tables, so it is a good idea to just memorize this ordering.
So, a visual representation of the 2-dimensional table variable, declared above,
would be:
table [0] [1] [2] [3] [4]
[0]
[1]
[2]
[3]
[4] 25
[5]
[6]
[7]
