Topic 3 - Fundamentals Of Programming Language (2)

Selection

▪ The expression which result on TRUE or
FALSE.

▪ Consists 2 keywords:

▪ if
▪ else

Selection

▪ The selection control structure can be
categorized into 4 groups :
1. if statement
2. if-else statement
3. if-else statement (nested)
4. Switch statement

IF Statement

▪ The IF statement will perform an action if
the condition is true and ignore the
action if the condition is false.

Example : IF Statement

if speed > 110 print “penalty”

Answer : Algorithm

1. Read speed
2. If speed more than 110, print “penalty”

Answer: Pseudo Code

Begin
Read speed

if speed> 110, print “penalty”
end if
End

Answer: Flow Chart

Begin

Read speed

Speed True Print
> 110 “Penalty”

False
End

EXERCISE..
▪ If marks < 40 print “fail”.

IF-ELSE Statement

▪ The IF statement will perform an action if the
condition is true and perform another action if
the condition is false.

Example: if-else statement

If speed > 110 print “penalty”
Else print “no penalty”

Answer : Algorithm

1. Read speed
2. If speed more than 110, print “penalty”
3. Else, print “no penalty”

Answer : Pseudo Code

Begin
Read speed

if speed> 110, print “penalty”
else print “no penalty”

end if
End

Answer : Flow Chart

Start

Read speed

Print “No False Speed True Print
Penalty” > 110 “Penalty”

End

EXERCISE..

If marks < 40 print “fail”
Else print “pass”

IF-ELSE Statement
(Nested)

▪ The IF-ELSE nested statement is a condition
when we have an ‘if’ in another ‘if’ body.

▪ We use this control structure if we have many
selection to be handle with.

▪ Syntax:

if ….
else if …

else …

Example : If-Else Nested
Statement

Create a program that can recognize and print
the price base on user prompt code. If user
enter a non-available value, the program will
print “Code Not Recognize”.

Code Price (RM)

1 2.00

2 4.00

3 6.00

4 8.00

Example: Algorithm

1.Read code
2. If code equal to one, then print “RM2.00”
3. Else if code equal to 2, then print “RM4.00”
4. Else if code equal to 3, then print “RM6.00”
5. Else if code equal to 4, then print “RM8.00”
6. Else print “Code Not Recognize”

Example: Pseudo Code

Begin
Read code
if code = 1

print “RM2.00”
else if code = 2

print “RM4.00”
else if code = 3

print “RM6.00”
else if code = 4

print “RM8.00”
else

Print “Code Not Recognized”
End

Example: Flow Chart

Start Print “Code
Not
Read
code Recognized”

F

Code F Code F Code F Code
=1 =2 =3 =4

T T T T

Print Print Print Print
“RM2.00” “RM4.00” “RM6.00” “RM8.00”

End

EXERCISE..

Develop a program which can determine

a driver expertise by count their training

day.

Training day Expertise

0 None

1-3 Weak

4 - 10 Average

>10 Expert

Switch Statement

Limitation Keyword

Can only Add Your Text
use for 2
data type, Switch
integer and break
character default
ONLY.

Switch Statement

switch ( Variable) void main ( )
{ case <caseValue> : {
Statement1; int Num;
Statement2; cin>>Num;
- switch (Num)
StatementN;
break ; { case 1 :
case <CaseValue> : cout<<”You choose 1.”;
statement1; cout<<Thank you!”;
statement2; break ;
break;
- case 2 :
- cout<<” You choose 2.”;
default : break ;
statement1
statement2; default :
} cout<< “ choose 1 or 2 only.”;
cout<< “understand!);

}
}

When user choose 1, system will display “You choose 1”,” Thank you”.

When user choose 2, system will display “You choose 2”

When user choose 88, system will display “choose 1 or 2 only”.”
understand!”.

#include <iostream> EXAMPLE 1
using namespace std;

int main ()
{

// local variable declaration:
char grade = 'D';

switch(grade)
{
case 'A' :

cout << "Excellent!" << endl;
break;
case 'B' :
case 'C' :
cout << "Well done" << endl;
break;
case 'D' :
cout << "You passed" << endl;
break;
case 'F' :
cout << "Better try again" << endl;
break;
default :
cout << "Invalid grade" << endl;
}
cout << "Your grade is " << grade << endl;

return 0;
}

REPETITION

Repetition

▪ Using loop structure.
▪ 3 types of loop:

▪ While
▪ Do .. While
▪ For

‘While’ Loop

▪ Repeat as pre-condition is true

while (condition)
{
loop body
}

‘While’ Loop

▪ The while construct consists of a block of code
and a condition.

▪ The condition is evaluated, and if the condition
is true, the code within the block is executed.

▪ This repeats until the condition becomes false.
▪ Because while loops check the condition

before the block is executed, the control
structure is often also known as a pre-test
loop.

‘While’ General

Condition True

Loop body

False

‘While’ Example

▪ Create a program that can print the value
which is less than 5.

‘While’ Pseudo Code

Begin
Read value= 0
while value < 5
Print value
value=value+1
end while

End

‘While’ Flow Chart

Start

Value = 0

Value =
Value + 1

Value < 5 ? True
False Print Value

End

‘While’ Source Code

‘Do-While’ Loop

⦿ Repeat as post-condition is true

do
{
loop body
}
while (condition)

‘Do-While’ Loop

▪ The do while construct consists of a block of
code and a condition.

▪ First, the code within the block is executed, and
then the condition is evaluated.

▪ If the condition is true the code within the block
is executed again. This repeats until the
condition becomes false.

▪ Because do while loops check the condition after
the block is executed, the control structure is
often also known as a post-test loop.

‘Do-While’ General

Loop body True
Condition

False

‘Do-While’ Example

▪ Create a program that can print the value which
is less than 5.

‘Do-While’ Pseudo code

Begin
Read value= 0
repeat
Print value
value=value+1
until value < 5

End

‘Do-While’ Flow Chart

Start

Value = 0

Print value Value = True
Value+1
Value < 5 ?
False

End

‘Do-While’ Source Code

‘For’ loop

▪ Suitable if we know the number of iterations.

for (expr1;expr2;expr3)
{
s1;
s2 ;
}

▪ expr1 is executed only once before looping.
▪ expr2 is a Boolean expression. If not given, it is

assumed to be true.
▪ If expr2 is false, the loop is terminated.
▪ After execution of the repeat section, expr3 is

executed.

‘For’ loop

▪ The for loop is often distinguished by an explicit
loop counter or loop variable.

▪ This allows the body of the for loop (the code
that is being repeatedly executed) to know
about the sequencing of each iteration.

▪ for loops are also typically used when the
number of iterations is known before entering
the loop.

‘For’ loop

1
2

5

for (i = 0, i < 5, i++)

p{ rintf(“the3numbers are %d 4 i);

\n”,

}

‘For’ Example

▪ Create a program that can print the value which
is less than 5.

‘For’ Pseudo code

Begin
Read value
For value < 5

Print value
value=value+1
End for
End

‘For’ Flow chart

Start

Value = 0

Value True
<5
Print value value ++

False
End

‘For’ Example