Introduction to Computer Programming - Repetition

1. Prepared by
T.A/ Ayman S. Abdelaziz

2. Lab Rules
 Put your cell phone in silent mode or switch it off.
 Shut down your PC monitor, tablet or laptop.
 Take a permission first before you leave or enter the
lab.
 Don’t write any attendance sheet, I will do this at the
end of our session.
 Don’t talk with your colleagues.

3. Session OUTLINE
 for Loop
 while loop
 do …while loop
 Lab Task
 Quiz 02

4. Types of Operations
Algorithms can be constructed for
• Sequential Operation (Previous)
• Conditional Operation (Previous)
• Iterative Operation (Today)

5. Operation of the for loop

6. for loop syntax
for ( initialization statement; test expression; update statement )
statement 1;
for ( initialization statement; test expression; update statement )
{ statement 1;
statement 2;
statement 3;
}

7. for loop syntax

8. #include <iostream>
using namespace std;
void main()
{
for(int a=10; a<20 ; a++)
cout<<"value of a: "<< a << endl;
}
Demonstrate for Loop
value of a: 10
value of a: 1 1
value of a: 1 2
value of a: 1 3
value of a: 1 4
value of a: 1 5
value of a: 1 6
value of a: 1 7
value of a: 1 8
value of a: 1 9

9. Operation of the while loop

10. while loop syntax
while (test expression)
statement 1;
while (test expression)
{ statement 1;
statement 2;
statement 3;
}

11. while loop syntax

12. #include <iostream>
using namespace std;
void main()
{
int a = 10;
while(a < 20)
{
cout<<"value of a: "<< a << endl;
a++;
}
}
Demonstrate while Loop
value of a: 10
value of a: 1 1
value of a: 1 2
value of a: 1 3
value of a: 1 4
value of a: 1 5
value of a: 1 6
value of a: 1 7
value of a: 1 8
value of a: 1 9

13. Operation of the do…while loop

14. do…while loop syntax
do
statement 1;
while (test expression);
do
{
statement 1;
statement 2;
statement 3;
}
while (test expression);

15. do…while loop syntax

16. #include <iostream>
using namespace std;
void main()
{
int a = 10;
do
{
cout<<"value of a: "<< a << endl;
a = a + 1;
} while(a < 20);
}
value of a: 10
value of a: 1 1
value of a: 1 2
value of a: 1 3
value of a: 1 4
value of a: 1 5
value of a: 1 6
value of a: 1 7
value of a: 1 8
value of a: 1 9
Demonstrate do…while Loop

18. Lab Task 1
Print your name 3 times using
1. for loop
2. while loop
3. do … while loop

20. #include <iostream>
using namespace std;
void main()
{
for(int n=10; n>0; n--)
{
cout<<n<<", ";
}
cout<<"FIRE!n";
}
10, 9, 8, 7, 6, 5, 4, 3, 2, 1 FIRE!

21. #include <iostream>
using namespace std;
void main()
{
int n;
cout<<"Enter the starting number> ";
cin>> n;
while(n>0)
{
cout<<n<<", ";
n--;
}
cout<<"FIRE!n";
}
10, 9, 8, 7, 6, 5, 4, 3, 2, 1 FIRE!

22. #include <iostream>
using namespace std;
void main()
{
int sum = 0;
for(int i=1; i<=3; i++)
{
sum += i;
}
cout<<"Sum is "<<sum<<endl;
}
Sum is 6

23. #include <iostream>
using namespace std;
int main()
{
int j; //define a loop variable
for(j=0; j<3; j++) //loop from 0 to 2,
cout << j * j << " "; //displaying the square of j
cout << endl;
return 0;
}
Slide 3- 23
0 1 4

24. #include <iostream>
#include <iomanip> //for setw
using namespace std;
int main()
{
int numb; //define loop variable
for(numb=1; numb<=3; numb++) //loop from 1 to 3
{
cout << setw(4) << numb; //display 1st column
int cube = numb*numb*numb; //calculate cube
cout << setw(6) << cube << endl; //display 2nd column
}
return 0;
}
1 1
2 8
3 27

25. #include <iostream>
using namespace std;
int main()
{
int numb;
long fact=1; //long for larger numbers
cout << "Enter a number: ";
cin >> numb; //get number
for(int j=numb; j>0; j--) //multiply 1 by
fact *= j; //numb, numb-1, ..., 2, 1
cout << "Factorial is " << fact << endl;
return 0;
}
Enter a number: 5
Factorial is 120

26. #include <iostream>
using namespace std;
int main()
{
int n = 99; // make sure n isn't initialized to 0
while( n != 0 ) // loop until n is 0
cin >> n; // read a number into n
cout << endl;
return 0;
}
1
27
33
144
9
0

27. #include <iostream>
using namespace std;
int main()
{
long dividend, divisor;
char ch;
do //start of do loop
{ //do some processing
cout << "Enter dividend: "; cin >> dividend;
cout << "Enter divisor: "; cin >> divisor;
cout << "Quotient is " << dividend / divisor;
cout << ", remainder is " << dividend % divisor;
cout << "nDo another? (y/n): "; //do it again?
cin >> ch;
}
while( ch != 'n' ); //loop condition
return 0;
}
Enter dividend: 11
Enter divisor: 3
Quotient is 3, remainder is 2
Do another? (y/n): y
Enter dividend: 222
Enter divisor: 17
Quotient is 13, remainder is 1
Do another? (y/n): n

29. Lab Task 2
Write equivalent statements for the following C++ program
fragment using while loop, and determine the output without
using any C++ compiler.
for(int j=0; j<3 ; j++)
cout << j * j << " ";

30. Home Assignment
 Will be published today on our facebook group.

31. Next Lab
Repetition (part 2)
Nested Loops
Other Control Statements (break & continue)
More Advanced Applications (conditions within loops)

32. How to find your course materials?
Via Facebook:
 Join this group:
https://www.facebook.com/groups/CS101.2015/
 And also this group:
http://facebook.com/groups/Must.CS101/

33. References
 Object-Oriented Programming in C++. 4th Edition, Robert
Lafore
 Introduction to Programming with C++, 2nd Edition, Y.
Daniel Liang
 Problem Analysis to Program Design, 3rd Edition

34. How to contact me?
 Office hours
TUE: 03:00 to 05:00 P.M
WED: 01:00 to 05:00 P.M
 You can also contact me through:
http://fb.com/ayman.shamel
Ayman_shamel@hotmail.com

35. 35