Control statements in C allow changing the order of execution based on conditions or repeating a group of statements. The main types of control statements are selection structures like if/else which execute one or the other block based on a condition being true or false, and looping structures like while, do-while and for loops which repeat a block of code either indefinitely or a specified number of times. Nested loops can also be used to repeat blocks of code multiple times in both the inner and outer loops.

1. Control Statement in C
Lecture : 7
Md. Al-Imran Roton
Lecturer, CSEDIU
Bangladesh

2. CONTROL STATEMENT
•All the statements written in ‘C’ program executes
from top to bottom one by one

3. CONTROL STATEMENT
There are some situations where one
may have to
Change the order of execution based on
certain conditions
OR
Repeat a group of statements until certain
conditions are satisfied.

4. TYPES OF CONTROL STATEMENT

5. IF SELECTION STRUCTURES
1) A simple if structure is called a single-selection
structure because it either selects or ignores a
single action.

6. IF/ELSE SELECTION
STRUCTURESThe if / else structure is called a double-
selection structure because it selects
between two different actions.

7. IF/ELSE SELECTION
STRUCTURES
Diagram of IF and Else

8. REAL LIFE
EXAMPLENeed to make a decision to go which way

9. Real life example
If(girl==educated&&beautiful&&smart)
{
then, I agree to marry her.
}
Else
{
I don’t agree to marry her.
}

10. START
Money Received 15000
Received
Money>=10000
?
Holiday Enjoyed
END
Condition not Satisfied
[False] Condition Satisfied
[True]
Holiday Trip Problem

11. Example code

12. Nested IF / ELSE
Lecturer : 8

13. Nested if condition

14. Real life example
• If(girl==educated)
• {
• If(girl==beautiful)
• {
• If(girl==smart)
• I agree to marry her.
• Else
• Think about consideration.
•
• }
• Else
• Talk with parents.
• }
• Else
• Rejected .

15. Elseif condition

16. Elseif condition
• stucture

17. Example

18. Switch statement
Syntax
switch(expression)
{
case value-1:
block-1;
break;
case value-2:
block-2;
break;
……………..
……………..
default
block;
break;
}
Statement - X

19. Switch statement

20. Switch statement

21. Example

22. Example

23. PRACTICE EXAMPLE
•Big Bazzar gives festival discount on purchase of
their products in the following percentages
i.If purchase amount < 1000 than 5% discount
ii.If purchase amount >=1000 than but <3000 then
10% discount
iii.If purchase amount >=3000 but <5000 then 12%
discount
iv.If purchase amount > 5000 then 15% discount
v.Make an university grading system.

24. Thank you

25. JUMPING
Lecturer : 9

26. Break Statement
• It is an jump instruction and can be
used inside the switch and loop
statements.
• The execution of the break statements
causes the control transfer to the
statement immediately after the loop.

27. Break Statement

28. Break Statement

29. Break Statement

30. Continue Statement
• It is a jump statement.
• It is used only inside the loop.
• Its execution does not exit from the loop but
escape the loop for that iteration and
transfer the control back to the loop for the
new iteration.

31. Continue Statement

32. Goto Statement
• It is used the alter the normal sequence of flow by
transferring the control to some other part of the
program unconditionally.
• It is followed by the label statement which
determine the instruction to be handled next after
the execution of the goto statement.

33. Goto Statement

34. Goto Statement

35. Example

36. Thank You

37. Repetition/Looping
Lecture : 10

38. Why Looping
HA HA
HA HA
HA HA
HA HA
HA HA
HA HA

39. Why Looping
• Printf(“HA HA ”);
• Printf(“HA HA ”);
• Printf(“HA HA ”);
• Printf(“HA HA ”);
• Printf(“HA HA ”);
• Printf(“HA HA ”);
• Need to write 6 time printf() function. (problem)
• Solution : Repitition/Looping.

40. Why looping

41. Types of Looping
• While
• Do while
• For

42. While loop

43. While loop

44. Infinity While loop
• while(1)
• {
• statements;
• ........
• }
• Question: How it will stop?

45. Infinity While loop
• Solution : Use “break” to exit from the loop
while(1)
{
statements;
........
if(condition)
break;
}

46. Example

47. Do while loop
• Difference from while:
•

48. Do while loop

49. Do while loop

50. Example

51. Thank you

52. FOR LOOP
Lecture:11

53. Syntax
• There are 3 parts in a for loop.
• 1. Initialization.
• 2. Condition.
• 3. Increment / Decrement.

54. Flowchart For loop

55. Flowchart For loop

56. Diagram of for loop

57. Diagram of for loop

58. Infinity for loop
• for( ; ; )
• {
• statements;
• ........
• }
• Same question How to stop the loop.
• Answer is also same use “break”.

59. Example
• Display 1 to 10.

60. Example
• Sum 1 to 10.

61. Example
• Sum 1 to n.

62. Thank you ……

63. NESTED FOR LOOP
Lecture: 12

64. What is nested loop
• There exits multiple loop like 2,3,4….so on.
• 1. Outer loop.
• 2. Inner loop.

65. Outer/Inner loop

66. Diagram of nested for loop

67. Example

68. Example

69. Example

70. Example

71. Some Interesting practice Example

72. Some Interesting practice Example

73. Some Interesting practice Example

74. Some Interesting practice Example

75. Some Interesting practice Example

76. Thank you……