The document introduces control structures in programming, emphasizing their importance in managing program flow through sequential, conditional, iterative, and branching methods. It provides definitions, examples, and types for each control structure, illustrating their practical applications in programming. The lecture aims to equip students with the ability to implement these structures effectively in their coding practices.

1. Control Structures of
Programming
Introduction to Programming Concepts
Presenter's Name : Amali Gunasinghe
MSc, BSc(Hons) in Information Technology(SLIIT)

2. Objectives
• At the end of this lecture, students should be able to:
• Understand the concept of control structures and their
importance in programming.
• Identify and differentiate between the types of control structures
sequential, conditional, iterative and branching .
• Implement and use control structures in programs.

3. What are Control Structures?
• A control structure is a fundamental concept in programming that
allows developers to control the flow of execution of a program.
• Control structures enable a program to make decisions, repeat tasks,
or execute code conditionally.
• Types of Control Structures:
• Sequential Control
• Conditional Control (Selection)
• Iterative Control (Loops)
• Branching Control

4. Sequential Control
• Definition: Instructions are executed one after another in a linear
order.
Example: imagine your morning routine:
• Brush your teeth.
• Have breakfast.
• Pack your bag.
• Go to school.
• In programming, this would look like:
print("Brush your teeth.")
print("Have breakfast.")
print("Pack your bag.")
print(“Go to school.”)

5. Conditional Control (Selection)
• Definition: Allows the program to make decisions based on
conditions.
IF
Condition?
Statement sequence 1
ENDIF
Statement sequence 2
False
True

6. Types of Conditional Statements:
• If Statement: Executes a block of code if a condition is true.
• If-Else Statement: Provides an alternative path if the condition is
false.
• Else-If Ladder: Multiple conditions are checked in sequence.
• Example:If-Else Statement
weather = "sunny"
if weather == "rainy":
print("Stay indoors.")
else:
print("Go for a walk.")

7. Else-If Example:
score = 85
if score >= 90:
print("Grade: A")
elif score >= 80:
print("Grade: B")
else:
print("Grade: C")

8. Iterative Control (Loops)
• Definition: Repeats a block of code multiple times.
• Types of Loops:
• For Loop: Repeats a known number of times.
• While Loop: Repeats as long as a condition is true.

9. For Loop
• Example:let's print "Practice makes perfect" five times to remind
ourselves
• range(5) generates numbers from 0 to 4
for i in range(5):
print("Practice makes perfect")

10. While Loop
• Example:While loop to print numbers from 1 to 5
• The while loop will continue to execute as long as the condition
number <= 5 is true.
# Initialize the variable
number = 1
while number <= 5:
print(number) # Print the current value of number
number += 1 # Increment the value of number by 1

11. Branching Control
• Definition: Controls the flow within loops.
• Types:
• Break: Exits the loop immediately.
• Continue: Skips the current iteration and moves to the next.
• Example
for i in range(10):
if i == 5:
break
print(i)

12. Summary
• Recap of Key Points:
• Sequential, Conditional, Iterative and Branching control structures
are fundamental for programming.
• Control structures help in decision-making and repeating tasks.
• Next Steps:
• Practice using different control structures in simple programs.
• Understand how they help in problem-solving.

13. Questions & Answers
• Do you have any questions about control structures? Feel free to ask!

14. References
1) B. W. Kernighan and D. M. Ritchie, The C Programming Language, 2nd ed. Upper Saddle River,
NJ, USA: Prentice Hall, 1988.
2) S. G. Kochan, Programming in C, 4th ed. Upper Saddle River, NJ, USA: Addison-Wesley
Professional, 2014.
3) M. Sipser, Introduction to the Theory of Computation, 3rd ed. Boston, MA, USA: Cengage
Learning, 2012.
4) GeeksforGeeks, "Control Structures in C," [Online]. Available: https://www.geeksforgeeks.org.
[Accessed: 27-Aug-2024].
5) TutorialsPoint, "Control Structures," [Online]. Available: https://www.tutorialspoint.com.
[Accessed: 27-Aug-2024].

15. Thank You
• "Thank you for your attention! Happy coding, and keep practicing!"
• Contact Information:
• Email: amali.gunasinghe5@gmail.com