1. Programming Fundamental
Instructor Name: Muhammad Safyan
Lecture-17

2. Lecture outline Character Arrays Passing Array to Function
Constant Arrays as Formal Parameters

3. Initializing Character Array
Initializing array of integers
int c [ 10 ] = { 1,2,3,4,5,6,7,8,9,10 } ;
int c [ ] = { 1,2,3,4,5,6,7,8,9,10 } ;
For character arrays
char name [ 100 ] = { ‘a’,b’,’c’,’0’,’1’ } ;
char name [ 100 ] = “abc01“ ;
char name [ ] = “Hello World“ ;

4. Character Arrays Displaying name on screen using loop
for ( i = 0 ; i < 100 ; i ++ ) {
cout << name [ i ] ; }

5. Comparing Two Arrays
AZMAT HAMEED
Azmat Hameed

6. Comparing Two arrays Array size should be equal
char a[5]={'a','b',' ', 'c','d'};
char b[5]={'A','B',' ', 'C','D'};
int equal=-1;
for (int i=0; i<5; i++)
if(a[i]!=b[i]) {
equal=1;
break; }
if (equal==1)
cout<<"Two array are not equal";
else
cout<<"Array are equal";

7. Handling space in array of chracters
char name[50];
cin.getline(name,50);

8. Exercise
Input your name and display it in reverse order

9. Functions and Arrays

10. Sending Arrays into Another Functions
Name of the array
Size of the array

11. Whenever a variable is passed , it is passed by value
Whenever you pass an array to
function, it is called by reference

12. In case of arrays , call by reference is default
& Address Operator
In case of arrays , call by reference is default

13. Example 1 char name [ 100 ] ; reverse ( name , 100 ) ; Declaration
Function Call

14. Example 1 void reverse ( char [ ] , int ) ; {
void reverse ( char characters [ ] , int arraySize) {
reverse the character string; }
Prototype
Definition

15. Example 1 main ( ) { cin >> name [ ] ;
reverse ( character [ ] , arraySize ) ;
cout << name [ ] ; }
What will it Show ?

16. X is a variable which is a location in the memory Name [ ] is an array
Starting address -
Array called Name
Memory
name

17. Example 2 void f ( int [ ] , int ) ; main ( ) { int numbers [ 100 ] ;
f ( numbers , 100) ;
for ( int i = 0 ; i < 100 ; i ++)
cout << numbers [ i ] ; }

18. Example 2 void f ( int x [ ] , int arraySize ) { int i ;
for ( i = 0 ; i < arraySize ; i ++)
x [ i ] = i ; }

19. Executed with call by value, not by reference
f ( x [ 3 ] ) ;
Executed with call by value, not by reference

20. Void f(int [], int);
main() {
const int n=10;
int nm[n];
for (int i=0; i<n; i++)
cin>>nm[i];
f(nm,n);
cout<<nm[i]<<endl;
getch(); }
Void f( int b[], int n1)
for (int i=n1; i>=0; i--)
b[i]=b[i]*2;;

21. Multidimensional Arrays

22. Matrix
Rows
Columns

23. Two Dimensional Array
int x [ 2 ] [ 3 ] ;

24. Example 3 int maxRows = 2; int maxCols = 3 ; int matrix [ 2] [ 3 ];
int row , col ;
for ( row = 0 ; row < maxRows ; row ++ ) {
for ( col = 0 ; col < maxCols ; col ++ )
cout << “Please enter value of ”<< row << “ “ << col;
cin >> matrix [ row ] [ col ] ; }

25. After second outer loop
After first outer loop
Input
[0] 5 2 9
After second outer loop
Input
[0] 5 2 9 7 4
[1]

26. Three Dimensional Arrays
int x [ ] [ ] [ ] ;

27. Array Manipulation

28. Example 1
Input 9 8 7 6 5 4 3 2 1
Row 1
Row 2
Row 3 9 8 7 6 5 4 3 2 1
Row 1
Row 2
Row 3
Memory 3 2 1 6 5 4 9 8 7
Row 1
Row 2
Row 3
Output

29. Addressing Array Elements
a [rowIndex ] [ columnIndex ]

30. Example 1 int row ; int col ; const maxRows = 3 ; const maxCols = 3 ;
int a [ maxRows ] [ maxCols ] ;

31. Example 1 { for ( col = 0 ; col < maxCols ; col ++ )
for ( row = 0 ; row < maxRows ; row ++ ) {
for ( col = 0 ; col < maxCols ; col ++ )
cout << “Please enter value of element number ”<<row<< “,” << col ;
cin >> a [ row ] [ col ] ; }

32. Example 2 maxRows = 3 ; maxCols = 3 ; 3 2 1 [0] [1] [2] Index of Start
Index of Last Row = maxRows - 1

33. Example 2 for ( row = maxRows - 1 ; row >= 0 ; row -- ) {
for ( col = 0 ; col < maxCols ; col ++ ) … }
Decrement Operator 9 8 7 6 5 4 3 2 1
Row 1
Row 2
Row 3 3 2 1 6 5 4 9 8 7
Row 1
Row 2
Row 3

34. Example 2: Formatted Output
cout << “The original matrix is” ;
for ( row = 0 ; row < maxRows ; row ++ ) {
for ( col = 0 ; col < maxCols ; col ++ )
cout << a [ row ] [ col ] ; }
<< ‘\t‘ ; 15 42

35. Example 2: Formatted Output
for ( row = 0 ; row < maxRows ; row ++ ) {
for ( col = 0 ; col < maxCols ; col ++ )
cout << a [ row ] [ col ] << ‘\t’ ; }
cout << ‘ \n ’ ;

36. Enter the values in a matrix and print it in reverse Column order
Exercise
Enter the values in a matrix and print it in reverse Column order 9 8 7 6 5 4 3 2 1
[0] [1] [2] 7 8 9 4 5 6 1 2 3
[2] [1] [0]

37. Transpose of a Matrix 1 2 3 4 5 6 7 8 9

38. Square Matrix arraySize = rows cols
Number of rows are equal to number of columns
arraySize =
rows
cols

39. Square Matrix
a ij = a ji
i = rows
j = columns

40. Square Matrix int a [ row ] [ col ] ; int arraySize ;
for ( row = 0 ; row < arraySize ; row ++ ) {
for ( col = 0 ; col < arraySize ; col ++ )
//Swap values }

41. Swap Mechanisms temp = a [ row ] [ col ] ;
a [ row ] [ col ] = a [ col ] [ row ] ;
a [ col ] [ row ] = temp ;

42. Practical Problem Problem statement
Given tax brackets and given employee gross salaries , determine those employees who actually get less take home salary than others with lower initial income

43. Rule for tax deduction 0 –> 5,000 No tax
– >10,000 5% Income Tax
10,001 – >20, % Income Tax
20,001 and more 15% Income tax

44. Example Net salary = Rs 10,001 Net salary = Rs 10,000 Tax = 5%
Amount Deducted = 5% of 10,000
= 500
Net amount after deduction = 10,
= 9,500
Net salary = Rs 10,001
Tax = 10%
Amount Deducted = 10% of 10,001
= 1,000.1
Net amount after deduction = 10, ,000.1
= 9,000.9

45. One- dim arrays of integer
Storage Requirement
One- dim arrays of integer
lucky = 0
lucky = 1

46. Storage of salary 1 5,000 2 10,000 9,500 3 4 5 6 7 8 9 10 No of Emp.
Grow Salary
Net Salary After Deduction 1
5,000 2
10,000
9,500 3 4 5 6 7 8 9 10

47. Interface Requirements

48. Distribution of the Program
Input
Salary calculation
Identification of the unlucky
individuals
Output

49. Detail Design Functions in the program getInput calculateSalary
locateUnluckyIndividual
displayOutput

50. Code #include<iostream.h>
void getinput ( int [ ] [ 2 ] , int ) ;
main ( ) {
const int arraySize = 100 ;
int sal [ arraySize ] [ 2 ] ;
int lucky [ arraySize ] = { 0 } ;
int numEmps ;
cout << “Enter the number of employess “ ;
cin >> numEmps ;
getInput ( sal , numEmps ) ; }

51. Code getInput ( int sal [ ] [2] , int numEmps ) {
for ( i = 0 ; i < numEmps ; i ++ )
cin >> sal [ i ] [ 0 ] ; }

52. Code { for ( i = 0 ; i < numEmps ; i ++ )
calculateSalary ( int sal [ ] [ 2 ] , int lucky [ ] , int numEmps ) {
for ( i = 0 ; i < numEmps ; i ++ )
// netSalary = grossSalary – tax
if ( sal [ i ] [ 0 ] <= 5000 )
sal [ i ] [ 1 ] = sal [ i ] [ 0 ] ; }

53. Code { if ( sal [ i ] [ 0 ] <= 10000 )
else {
if ( sal [ i ] [ 0 ] <= )
sal [ i ] [ 1 ] = sal [ i ] [ 0 ] *sal [ i ] [ 0 ] ; }

54. Code else { if ( sal [ i ] [ 0 ] <= 20000 )
sal [ I ] [ 1 ] = sal [ I ] [ 0 ] * sal [ I ] [ 0 ] ; }

55. Code
else {
sal [ i ] [ 1 ] = sal [ i ] [ 0 ] * sal [ i ] [ 0 ] ; }

56. if ( sal [ i ] [ 0 ] >= 0 && sal [ i ] [ 0 ] <= 5000 ){
sal [ i ] [ 1 ] = sal [ i ] [ 0 ] ; }
if ( sal [ i ] [ 0 ] > 5000 && sal [ i ] [ 0 ] < )
sal [ i ] [ 1 ] = sal [ i ] [ 0 ] * sal [ i ] [ 0 ] ;
... … …

57. if ( grossSalary > sal [ i ] [ 0 ] && netSalary < sal [ i ] [ 1 ] )
This logic will fail

58. Code
void locateUnluckyIndividual ( int sal [ ] [ 2 ] , int lucky [ ] , int numEmps ) {
int i , j ;
int grossSalary , netSalary ;
for ( i = 0 ; i < numEmp ; i ++ )
grossSalary = sal [ i ] [ 0 ] ;
netSalary = sal [ i ] [ 1 ] ;
for ( j = 0 ; j < numEmp ; j ++ )
if ( grossSalary > sal [ j ] [ 0 ] && netSalary < sal [ j ] [ 1 ] )
lucky [ i ] = 1 ; }

59. Code { for ( i = 0 ; i < numEmp ; i ++ ) if ( lucky [ i ] == 1 )
void displayOutput ( int sal [ ] [ 2 ] , int lucky [ ] , int numEmps ) {
for ( i = 0 ; i < numEmp ; i ++ )
if ( lucky [ i ] == 1 )
cout<< “Employee No.” << i+1 << “ is unlucky, Gross Salary = ” << sal [ i ] [ 0 ] << “ Net Salary = ” << sal [ i ] [ 1 ] << “\n” ; }

60. Exercise
Suppose you are given a square matrix of size n x n , write a program to determine its multiplication.

61. Exercise
Suppose you are given a square matrix of size n x n , write a program to determine if this is an identity matrix