Loops

1. while() and do while()

2. While () loop in C
• while loop has one control condition, and
executes as long the condition is true.
• The condition of the loop is tested before the
body of the loop is executed.
• It is also called an entry-controlled loop.

3. Syntax of while() Loop
While (condition)
{
statement(s);
Incrementation;
}

4. Flowchart of while() Loop

5. Example: Factorial Program Using While
Condition
True Execute Body of Loop
Increment or decrement
False Execute Rest of
Statement

6. Cont’d

7. Example: Fibonacci Series Using While

8. Cont’d

9. Example: Fibonacci Series upto some number Using While

10. Cont’d

11. do while() Loop in C
• do while loops are very similar to the while
loops.
• But it always executes the code block at least
once and furthermore as long as the condition
remains true.
• This is an exit-controlled loop.

12. Syntax of do while() Loop
do
{
statement(s);
}
while( condition );

13. Flowchart of do while() Loop

14. Example: Count Number of Digits of Integer Using Do While
START with do Keywords
Execute Body of Loop,
increment/decrement
Condition

15. Cont’d

16. Example: find first and last digit of number Using Do While

17. Cont’d

18. Difference between
do while(), while() and for()
loops

19. Program using Do While() Loop
EXIT
Controlled

20. Cont’d

21. Program using While() Loop
ENTRY
Controlled

22. Cont’d

23. Program using for() Loop
ENTRY
Controlled

24. Cont’d

25. switch Statement in C
• The switch case statement is used when we
have multiple options and we need to
perform a different task for each option.

26. Syntax of switch Statement
switch(variable)
{
case 1: //execute your code
break;
case n: //execute your code
break;
default: //execute your code
break;
}

27. Flowchart of switch statement

28. Example: Select Color Using switch statement
Variable or
Expression

29. Cont’d

30. Example: print day of week name using switch case

31. Cont’d