2D array in C++ language ,define the concept of c++ Two-Dimensional array .with example .and also Accessing Array Components concept.and Processing Two-Dimensional Arrays.

1. Topic:
2D Array
Group Members:
 Ehatsham Riaz

2. Array:
 Consecutive group of memory locations
― All of which have the same type
Index:
 Position number used to refer to a specific
location/element
 Place in square brackets
― Must be positive integer or integer expression
 First element has index zero

3. Definition:
Two-dimensional Array: a
collection of a fixed number of
components arranged in two
dimensions
All components are of the same type

4. Syntax:
 The syntax for declaring a two-dimensional array
is:
DataType ArrayName[rowsize][colsize];
where rowsize and colsize are expressions yielding
positive integer values
Example: int data[3][4];
― Data is a TWO Dimensional array of size 3*4
elements

5.  The two expressions rowsize and colsize specify
the number of rows and the number of columns,
respectively, in the array
 Two-dimensional arrays are sometimes called
matrices or tables
 Multiple arrays of the same type can be declared
in a single declaration
―Use a comma-separated list of names and
sizes

6. int sales[10][5];

7. Each array Element is identified by its Row and
column position

8. Accessing Array Components
 The syntax to access a component of a two-
dimensional array is:
arrayName[indexexp1][indexexp2]
where indexexp1 and indexexp2 are expressions
yielding nonnegative integer values
 indexexp1 specifies the row position and
indexexp2 specifies the column position

9. inStock[1][3]=15;

10. Processing Two-Dimensional
Arrays:
 A two-dimensional array can be processed
in three different ways:
1. Process the entire array
2. Process a particular row of the array, called
row processing
3. Process a particular column of the array,
called column processing

11.  Each row and each column of a two-dimensional
array is a one-dimensional array
 When processing a particular row or column of a
two-dimensional array
― we use algorithms similar to processing one-
dimensional arrays

12. Example:

16. Initialisation of 2D Array
#include <iostream>
int main()
{
int _2DArray[5][6] = { { 1, 2, 3, 4, 5, 6},
{ 7, 8, 9, 0, 1, 2},
{ 3, 4, 5} };
for (int i = 0; i < 5; i++)
{
for (int j = 0; j < 6; j++)
{
cout << _2DArray [i][j];
}
cout << endl;
}
cout << endl;
return 0;
}

17. Output:
1 2 3 4 5 6
7 8 9 0 1 2
3 4 5 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0

18. Example
Write a function in c++ which accepts a 2D array of integers
and its size as arguments and displays the elements of middle
row and the elements of middle column.
const int S = 5;
void DisplayMidle( int A[S][S], int S)
{ int mid = S/2;
int i;
cout << “ n Middle row”;
for (i=0 ; i<S; i++)
cout << A[ mid ][ i ]<< “ “;
cout<< “ n Middle Column ”;
for (i = 0; i<S; i++)
cout<<A[i][ mid ]<< “ “
cout << endl;
}

19. Thank You 