50
4 Department of Business Computer Faculty of Business Administrator Ratchaphreuk College 4 (Control Structures) (Control Structures) 121002 Introduction to Computer Programming 1

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โครงสร้างควบคุม IF ELSE และ switch case

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Page 1: chapter4_1

����� ����� 44

Department of Business Computer

Faculty of Business Administrator

Ratchaphreuk College

����� ����� 44���� ���������� ������(Control Structures)(Control Structures)

121002 Introduction to Computer Programming1

(Control Structures)(Control Structures)

Page 2: chapter4_1

��� �!"#$%

� 3.1 $)��*�+,� (Algorithm)

� 3.2 ���./��0� (Pseudocode)� 3.2 ���./��0� (Pseudocode)

� 3.3 ���� ������ (Control structure)

� 3.4 ���� 1 �23 .�� (Sequence structure)

� 3.5 ���� 5��� /26!$ if

121002 Introduction to Computer Programming2

3.5 ���� 5��� /26!$ if

� 3.6 ���� 5���2 0� /26!$ switch

Page 3: chapter4_1

��� �!"#$%

� 3.8 ���� 5��$ �3 =>3 while

� 3.7 ���� 5��$ �3 =>3 for � 3.7 ���� 5��$ �3 =>3 for

� 3.9 ���� 5��$ �3 =>3 do/while

� 3.10 �3 ��� break 52) continue

121002 Introduction to Computer Programming3

Page 4: chapter4_1

��� �!"#$%

� 3.11 $)��*�+,�$ �� (Formulating Algorithm)� $G�"#$% 1, $ �3 =>3 �.0IJ�1��*����� � $G�"#$% 1, $ �3 =>3 �.0IJ�1��*�����

(Case Study 1, Counter-Controlled Repetition)

� 3.12 $)��*�+,�$ �� �.0IJ��+,�$ /$2 K $�*22L (Formulating Algorithm with Top-Down, Stepwise Refinement) � $G�"#$% 2, $ �3 =>3 �.0IJ��L 1�K1 ���

121002 Introduction to Computer Programming4

� $G�"#$% 2, $ �3 =>3 �.0IJ��L 1�K1 ��� (Case Study 2, Sentinel-Controlled Repetition)

� $G�"#$% 3, ���� ������5��=�!* (Case Study 3, Nested Control Structure)

Page 5: chapter4_1

3.1 $)��*�+,� (Algorithm)

� $)��*�+,�I*���*�> �6! $)��*$ I*$ 5$�MNO� �.0K)M)$!�.��0 �>*1!* !M)$!�.��0 �>*1!* !

� $ $)�3

� 23 .�� !$ $)�3

121002 Introduction to Computer Programming5

Page 6: chapter4_1

3.2 ���./��0� (Pseudocode)

� ���./��0� �6! P % !0L Q�L/MR*� $ ���ST�/ �0*�M5$�IJ�I*$ U�V* $)��*�+,� I*$ U�V* $)��*�+,�

� ��2�$%G)�2� 0P % ���IJ�I*J��+1M)K3 ��* =#�IJ�L 052)/ �0*Q.��.0�).�$ Q�LQ.�/MR*P % ���IJ�I*$ / �0*�M5$�K+ W

� Q�L�3 *�*�!�U+�/1!X 51LK)JL�0I��ST�/ �0*�M5$� Y�+.Z $L!*���K)/ �0*�M5$�!!$� $ IJ����./��0��3 I��ST�/ �0*

121002 Introduction to Computer Programming6

$L!*���K)/ �0*�M5$�!!$� $ IJ����./��0��3 I��ST�/ �0*�M5$�Q�L1�!QM$��2$����O2�$%GX0�L0 $���P % �M5$� (/JL* C �6! Java) �����I��IJ� 52)� � ]K.KL!!0TL$��$)��*�+,����IJ�5$�MNO� K+ W

Page 7: chapter4_1

3.3 ���� ������ (Control structure)

� �M5$���$�M5$�� � ]/ �0* #>*Q.��.0IJ����� � �3 $ ������/U�0 3 J*+./�L *�>* �6! � �3 $ ������/U�0 3 J*+./�L *�>* �6!

� ���� 1 �23 .�� (Sequence structure)

� ���� � /26!$ (Selection structure)

� ���� $ �3 =>3 (Repetition structure)

121002 Introduction to Computer Programming7

Page 8: chapter4_1

3.4 ���� 1 �23 .�� (Sequence structure)

� /MR*���� !�3 �������!�U+�/1!XK)�3 *QM1 �23 .�����/ �0*Q�� ]� Q�LQ.�/M2��0* �>*1!*$ �3 *�6!1 �23 .�����/ �0*Q�� ]� Q�LQ.�/M2��0* �>*1!*$ �3 *�6!��/6�!*Q /U+��/1+�

121002 Introduction to Computer Programming8

Page 9: chapter4_1

1��!0L Flowchart !���� 1 �23 .�� !P % =�

121002 Introduction to Computer Programming9

Page 10: chapter4_1

3.5 ���� 5��� /26!$ if

� ���� 5��� /26!$ if �6! ���� �3 ���IJ�/26!$�3 �3 ��� (�6!$2�L��3 ���) �.0! "�0$ 1�K�!�/6�!*Q =#��3 ��� (�6!$2�L��3 ���) �.0! "�0$ 1�K�!�/6�!*Q =#��� 3 TM5���6!� 1. �*#�� /26!$ (One Alternative)

� 2. �!� /26!$ (Two Alternative)

� 3. �2 0� /26!$ (Multiple-Alternative)

121002 Introduction to Computer Programming10

� 3. �2 0� /26!$ (Multiple-Alternative)

Page 11: chapter4_1

3.5.1 ���� 5��� /26!$ if )*+,-� /26!$

� ���� 5��*�> K)/26!$�3 �3 ��� (�6!$2�L��3 ���) $_1L!/�6�! 1�K�!�/6�!*Q 52��/MR*K+1�K�!�/6�!*Q 52��/MR*K+

� 1��!0L Flowchart !���� 5��� /26!$ if )*+,- � /26!$

��������condition

TRUEFALSE

121002 Introduction to Computer Programming11

condition

�����������������������statement T

Page 12: chapter4_1

TM5�� !���� 5��� /26!$ if )*+,-� /26!$

TM5��$ �3 1 �3 ��� :

if (condition) if (condition) Statement T;

TM5��$ �3 $2�L��3 ��� :if (condition){

121002 Introduction to Computer Programming12

if (condition){ True task;}

Page 13: chapter4_1

1��!0L !���� 5��� /26!$ if )*+,- � /26!$

1��!0L 1 : if (x > 0)

x > 0

total = total * x total = total * x;

1��!0L 2 : if (x > y) {

temp = x;x = y;

total = total * x

x > y

temp = x

121002 Introduction to Computer Programming13

temp = x;x = y;y = temp;

}

temp = xx = yy = temp;

Page 14: chapter4_1

1��!0L if )*+,- � /26!$ 1��!0L 1 : if (x > 0)

#include <iostream.h>#include <conio.h>int main(){

float x, total;cout << "input x : ";cin >> x;cout << "\n"; if (x > 0)

total = total * x;cout << "\n";cout << "input total : ";cin >> total;cout << "\n";

if (x > 0){

total = total *x;cout << "x= " << x << " total= " << total;

121002 Introduction to Computer Programming14

cout << "x= " << x << " total= " << total;} getch();return 0;

}

Page 15: chapter4_1

1��!0L if )*+,- � /26!$ 1��!0L 2 :

if (x > y) {

#include <iostream.h>#include <conio.h>int main(){

float x, y, temp;cout << "input x : ";cin >> x;cout << "\n"; {

temp = x;x = y;y = temp;

}

cout << "\n";cout << "input y : ";cin >> y;cout << "\n";

if (x > y){

temp = x;x = y;

121002 Introduction to Computer Programming15

x = y;y = temp;cout << "x= " << x << " y= " << y;

} getch();return 0;

}

Page 16: chapter4_1

3.5.2 ���� 5��� /26!$ if ./- � /26!$

� ���� 5��*�>���!� /26!$ $2L ��6! /26!$�3 �3 ��� (�6!$2�L��3 ���) /�6�!1�K�!�/6�!*Q 52��/MR*K+ �6! �3 �3 ��� (�6!$2�L��3 ���) /�6�! 1�K�!�/6�!*Q 52��/MR*/�_K $2�L��3 ���) /�6�! 1�K�!�/6�!*Q 52��/MR*/�_K

� 1��!0L Flowchart !���� 5��� /26!$ if ./- � /26!$

��������condition

TRUEFALSE

121002 Introduction to Computer Programming16

�����������������������statement T

�����������������������statement F

Page 17: chapter4_1

TM5�� !���� 5��� /26!$ if ./-� /26!$

TM5��$ �3 1 �3 ��� :if (condition){{

statement T ;} else {

statement F ; }

TM5��$ �3 $2�L��3 ��� : if (condition)

121002 Introduction to Computer Programming17

if (condition)

{ true task;

} else {false task;

}

Page 18: chapter4_1

1��!0L !���� 5��� /26!$ if ./- � /26!$ 1��!0L 1 : if (x >= 0)

cout << "positive\nZ;elseelse

cout << Ynegative\nZ;

1��!0L 2 : if (x>y) { temp = x ; x = y ; y = temp ;

121002 Introduction to Computer Programming18

x = y ; y = temp ;} else {

cout << Y x smaller y \nZ; }

Page 19: chapter4_1

#include <iostream.h>#include <conio.h>int main(){

float x;cout << "input x : ";cin >> x;

1��!0L 1 :

if (x >= 0)cout << "positive\nZ;

else cin >> x;cout << "\n";

if (x >= 0){

cout << " positive \n";} else {

cout << " negative \n";}

elsecout << Ynegative\nZ;

x >= 0

cout << "positive\n”

yes no

121002 Introduction to Computer Programming19

}getch();return 0;

}

cout << " negative\n”cout << "positive\n”

Page 20: chapter4_1

#include <iostream.h>#include <conio.h>int main(){

float x, y, temp;cout << "input x : ";cin >> x;cout << "\n";cout << "input y : ";

1��!0L 2 :

if (x>y) { temp = x ;

x = y ; cout << "input y : ";cin >> y;cout << "\n";

if (x > y){

temp = x;x = y;y = temp;

temp = x ;x = y ;y = temp ;

} else {cout << Yx smaller y \nZ;

}

121002 Introduction to Computer Programming20

cout << "x= " << x << " y= " << y;} else {

cout << "x smaller y \n"; }

getch();return 0;

}

Page 21: chapter4_1

3.5.3 ���� 5��� /26!$ if )012 � /26!$� ���� 5��*�>���2 0� /26!$ $2L ��6! I*$G����1�K�!�/6�!*Q

52�� �3 I��/$+.� /26!$ !$ �3 �3 ���� $$�L 2 � /26!$ � � ]IJ����� 5��� /26!$ if �2 0� /26!$�.0�3 $ �M5$�I��!0TLI*TM MultipleqAlternativeMultipleqAlternative

�������������� if

condition��� 1

���� ����

condition��� 2

�������������� else if �� �!

����

condition��� 3

�������������� else if ��#�

����

����

condition

����

���� ����

121002 Introduction to Computer Programming21

else if ��#�condition

��� n�������������� else if ��$%�&�'

�������������� else

���� ����

Page 22: chapter4_1

TM5�� !���� 5��� /26!$ if )012 � /26!$

TM5��: if (condition 1) {

statement 1; if (condition 1) {

statement 1;} else if (condition 2) {

statement 2;::

} else if (condition n) {

121002 Introduction to Computer Programming22

} else if (condition n) {statement n;

} else { statement;}

Page 23: chapter4_1

1��!0L !���� 5��� /26!$ if )012 � /26!$

Ex1. �+,&#�-.���.,/% 0 1�2���� ��1��3����.,����+�,&�����4�#5����6� '!���7�8�9� .&�:%&�., ;-�'< �.,������+�! .8�.,.+ 7�8�9�.8!����

!��������81<7=>1� 1. ������� ������ ������� � ��������2. ����� ����� !��"� ������#$�������%&���'��(� ����� !��"� ������#$�������%&���� ����� !��"� ������#$�������%&�����" 3. ��� %

;-�'< �.,������+�! .8�.,.+ 7�8�9�.8!����

121002 Introduction to Computer Programming23

3. ��� % num � ������� �count_0 � "� ���#$�������%&���'��(�

count_plus � "� ���#$�������%&�����" count_minus � "� ���#$�������%&����

Page 24: chapter4_1

1��!0L !���� 5��� /26!$ if )012 � /26!$ ,?��#�!�������� 1. "$����67�� 8��������"����� % �7�� � count_0 � "� ���#$�������%&���'��(� count_plus � "� ���#$�������%&�����" count_plus � "� ���#$�������%&�����" count_minus � "� ���#$�������%&���� 2. ��������%&������

num � ������� � 3. � �#!������� 9���%&�'��(� �����������'��(���8��67���:������ 9��;�7�<767��%&�'��(� ���� �#!���7��%&���������"� =�;�7

121002 Introduction to Computer Programming24

9��;�7�<767��%&�'��(� ���� �#!���7��%&���������"� =�;�7 9���<7 �������������"��8��67���:������

9��;�7�<7 ��������������8��67���:������4. !��������:� 3 67� 5. #�"� $����

Page 25: chapter4_1

1��!0L !���� 5��� /26!$ if )012 � /26!$

/*increment count_plus , count_minus an$ count_0 depending on x*/if (x > 0) {if (x > 0) {

count_plus = count_plus + 1;} else if (x < 0) {

count_minus = count_minus + 1;} else {

121002 Introduction to Computer Programming25

} else {

count_0 = count_0 + 1; }

Page 26: chapter4_1

1��!0L !���� 5��� /26!$ if )012 � /26!$ start

count_0 = 0, count_plus = 0,count_minus = 0

read num

1 !�

yescount_o=count_o+1 num > 0

yes no

no

count_plus=count_plus+1 count_minus=count_minus+1

read num

num = 0

121002 Introduction to Computer Programming26

print count_0, count_plus, count_minus

end

Page 27: chapter4_1

#include <iostream.h>#include <conio.h>int main(){

int count_0=0, count_plus=0,count_minus=0;float num;cout << "num : ";cin >> num;cout << "\n";cout << "\n";

if (num == 0){

count_0 = count_0+1;} else if (num > 0) {

count_plus = count_plus+1;} else {

count_minus = count_minus+1;}

121002 Introduction to Computer Programming27

cout << "count_0 = " << count_0 << "\n" ;cout << "count_plus = " << count_plus << "\n" ;cout << "count_minus = " << count_minus << "\n" ;

getch();return 0;

}

Page 28: chapter4_1

++LM!1% if �2 0 � /26!$ ���,�'�N���� .8O7� !�� %���P�!���+7�8���'� ��� +3�,��%�+7�8���'����#�'$,#�N-&��� %���? #�'$��!!�3� 10 7Q �+7�8�����?�.8 2 R&#�R� #�'$��!!�3� 3 7Q S2� 10 7Q �+7�8�����?�.8 1 R&#�R� #�'$��!!�3� 1 7Q S2� 3 7Q �+7�8�����?�.8 1/2 R&#�R� #�'$��!!�3� 1 7Q S2� 3 7Q �+7�8�����?�.8 1/2 R&#�R� �!�!�%S2� 1 7Q 1&���+7�8���

!��������81<7=>1� 1. ������� ������ ��(@ (age)2. ����� ���� ��% F��(������(@

��(@��""�7� 10 %G ��% F��6 �:�F 2 <���<�

121002 Introduction to Computer Programming28

��(@��""�7� 10 %G ��% F��6 �:�F 2 <���<� ��(@��""�7� 3 %G 9�� 10 %G ��% F��6 �:�F 1 <���<� ��(@��""�7� 1 %G 9�� 3 %G ��% F��6 �:�F 1/2 <���<� "�"8�9�� 1 %G ���� ��% F��

Page 29: chapter4_1

,?��#�!�������� (Flowchart)

start

yes no

read Age

Age > 10Age > 3 && Age <=10

yesEat = 2 Age > 3

yes no

no

Eat = 1

Age > 10

Age > 1 no

Eat = 0.5 Eat = 0

Age > 1 && Age <=3

121002 Introduction to Computer Programming29

print Eat

end

Page 30: chapter4_1

Source Code

121002 Introduction to Computer Programming30

Page 31: chapter4_1

1��!0L start

x <= 25

x=1, count_0 = 0, count_plus = 0,count_minus = 0

read num

endyes

no

�* Loop

yescount_o=count_o+1 num > 0

yes no

no

count_plus=count_plus+1 count_minus=count_minus+1

read num

num = 0

121002 Introduction to Computer Programming31

print count_0, count_plus, count_minus

x = x + 1

Page 32: chapter4_1

#include <iostream.h>#include <conio.h>int main(){

int x, count_0=0, count_plus=0,count_minus=0;float num;

for (x=1; x<=5; x++){ // start Loop for

cout << "num : ";cin >> num;

�* Loop For

cin >> num;cout << "\n";

if (num == 0){

count_0 = count_0+1;} else if (num > 0) {

count_plus = count_plus+1;} else {

count_minus = count_minus+1;}

121002 Introduction to Computer Programming32

} // end Loop for

cout << "count_0 = " << count_0 << "\n" ;cout << "count_plus = " << count_plus << "\n" ;cout << "count_minus = " << count_minus << "\n" ;

getch();return 0;

}

Page 33: chapter4_1

#include <iostream.h>#include <conio.h>int main(){

int x=1, count_0=0, count_plus=0,count_minus=0; // "$����67�� 8�����float num;

while (x <= 5) // ��=���;���"� �� ��{ // start Loop while

cout << "num : ";cin >> num;

�* Loop While

cin >> num;cout << "\n";

if (num == 0){

count_0 = count_0+1;} else if (num > 0) {

count_plus = count_plus+1;} else {

count_minus = count_minus+1;}

"� ��8��67����"����� %

121002 Introduction to Computer Programming33

x++; // "� ��8��67����"����� % }// end Loop while

cout << "count_0 = " << count_0 << "\n" ;cout << "count_plus = " << count_plus << "\n" ;cout << "count_minus = " << count_minus << "\n" ;

getch();return 0;

}

Page 34: chapter4_1

5��wx$��.1. ��������� !"�#$��%&'#��(%!)*%��+ ,- .�$+/�01234 1 �� 567&*8%&9:�;5��

'!8%&2+/�5<"�� !" *%��+ ,- .�5(=:;�� >"?� �@)234A$8A� �!(+"� !" �B%1. (1 !%D)

�8 �� �!�%

80 ,2?�:7 A

70 c 80 B

60 - 70 C

50 - 60 D

121002 Introduction to Computer Programming34

50 - 60 D

�&#'!�3� 50 F

Page 35: chapter4_1

1 !�start

yesgrade = 'A' score >= 70

yes no

no

read name, score

score >= 80

grade = 'A' score >= 70 no

grade = iB' yesscore >= 60 no

grade = iC' yes score >= 50 no

grade = iD' grade = iF'

121002 Introduction to Computer Programming35

print name, grade

end

Page 36: chapter4_1

#include <iostream.h>#include <conio.h>int main(){

float score; char grade;cout << "enter score : ";cin >> score;cout << "\n";

if (score >= 80){

grade = 'A';} else if (score >= 70 && score < 80) {

grade = 'B';} else if (score >= 60 && score < 70) {

grade = 'C';} else if (score >= 50 && score < 60) {

grade = 'D';

if (score >= 80){

grade = 'A';} else if (score >= 70) {

grade = 'B';} else if (score >= 60) {

grade = 'C';} else if (score >= 50) {

grade = 'D';

121002 Introduction to Computer Programming36

grade = 'D';} else {

grade = 'F';}

cout << "Grade is ==> " << grade << "\n "; getch();return 0;

}

grade = 'D';} else {

grade = 'F';}

Page 37: chapter4_1

read name, score

yes no

yesgrade = 'A' score >= 70 no

score >= 80

yesno score >= 0 && score <=100

yesgrade = 'A' score >= 70 no

grade = iB' yesscore >= 60 no

grade = iC' yes score >= 50 no

grade = iD' grade = iF'

121002 Introduction to Computer Programming37

print name, grade

endprint "** input valid ** G

Page 38: chapter4_1

int main(){

float score; char grade;cout << "enter score : ";cin >> score;cout << "\n";

if (score >= 0 && score <=100){

if (score >= 80) if (score >= 80) {

grade = 'A';} else if (score >= 70) {

grade = 'B';} else if (score >= 60) {

grade = 'C';} else if (score >= 50) {

grade = 'D';} else {

grade = 'F';}

121002 Introduction to Computer Programming38

}cout << "Grade is ==> " << grade << "\n ";

} else { cout << "** input valid ** \n";

}

getch();return 0;

}

Page 39: chapter4_1

5��wx$��.

2. ��������� !"�#$��%&'#��(%!)*%��+ ,- .�$+/�01234 1 ������ 10 �� �� 567&*8%&9:�;5�� '!8%&2+/�5<"�� !" *%��+ ,- .�5(=:;�� >"?� �@)234A$8A� �!(+"� !" �B%

�8 �� �!�%

80 ,2?�:7 A

70 c 80 B

60 - 70 C

50 - 60 D

121002 Introduction to Computer Programming39

�&#'!�3� 50 F

Page 40: chapter4_1

#include <iostream.h>#include <conio.h>int main(){

int x;float score;char grade; cout << " Report \n";cout << " ----------------------\n";

for (x=1; x<= 10; x++){

cout << "Enter score : ";cin >> score;cout << "\n";

if (score >= 0 && score <=100){

if (score >= 80){

grade = 'A';grade = 'A';} else if (score >= 70) {

grade = 'B';} else if (score >= 60) {

grade = 'C';} else if (score >= 50) {

grade = 'D';} else {

grade = 'F';}cout << "Grade is ==> " << grade << "\n\n ";

121002 Introduction to Computer Programming40

cout << "Grade is ==> " << grade << "\n\n "; } else {

cout << "** input valid **\n\n";}

} // loop for

cout << "----------------------\n"; getch();return 0;

}

Page 41: chapter4_1

#include <iostream.h>#include <conio.h>int main(){

int x=1;char grade;float score;

while (x <= 5){

cout << "enter score : ";cin >> score;cout << "\n";

if (score >= 0 && score <=100){

if (score >= 80){

grade = 'A';grade = 'A';} else if (score >= 70) {

grade = 'B';} else if (score >= 60) {

grade = 'C';} else if (score >= 50) {

grade = 'D';} else {

grade = 'F';}cout << "Grade is ==> " << grade << "\n\n ";

} else {

121002 Introduction to Computer Programming41

} else { cout << "** input valid **\n\n";

}x++;

} // loop while

cout << " ---------------------\n";getch();return 0;

}

Page 42: chapter4_1

3.6 ���� 5���2 0� /26!$ switch

� ���� 5���2 0� /26!$ switch K)]T$IJ��L!0I*$G� ! $ /26!$�*#�� /26!$I*�2 0W� /26!$ �.0�L ��� ! $ /26!$�*#�� /26!$I*�2 0W� /26!$ �.0�L ���IJ�1�K�!� K)1�!/MR*K3 *�*/1_� (int) �6! �!�T2J*+.1��!�$%(char) 51LK)1�!Q�L/MR*K3 *�*K+5��0 �(double) �.0! KK)!0TLI*TM !1��5M, *+UK*X �6!yN$XJ�*$_Q.�

121002 Introduction to Computer Programming42

yN$XJ�*$_Q.�

Page 43: chapter4_1

TM5�� !���� 5���2 0� /26!$ switch TM5��: switch (controlling expression)

{ case lable_set1:

statements1 case lable_set1:

statements1break;

case label_set2:statements2break; :

:

121002 Introduction to Computer Programming43

: case lable_setn:

statementsnbreak;

default : }

Page 44: chapter4_1

1��!0L : switch (ch)// $ 1�K�!�/6�!*Q ! switchK)*3 �L !1��5M���$3 �*.Q��I*�/2_��2� switch (int �6! char) QM1�K�!�$���L ����I*51L2)$G� {

#include <iostream.h>#include <conio.h>int main(){char ch;cout << "select ch ==> ";cin >> ch;

switch (ch) {case zB| :case zb| :cout << "Bat\nZ;break ;

case zC| :case zc| :cout << "Cat\nZ;

switch (ch) {

case 'B' :case 'b' :

cout << "Bat\n";break ;

case 'C' :case 'c' :

cout << "Cat\n";break ;

default :

121002 Introduction to Computer Programming44

cout << "Cat\nZ;break ;

default :cout << "Unknown clss \nZ << ch;

}

default :cout << "Unknown clss \n" << ch;

} getch();return 0;

}

Page 45: chapter4_1

5��wx$��.

3. ���*3?�>0!5 !&A�:+ .�;�&�9�:B% �!2����� "8�?���<+4� case "+��3/ ��I�"AI8 " 1 ������'B/�234<34�I:34?&�(J!+< ��I�"AI8 " 1 ������'B/�234<34�I:34?&�(J!+< " 2 ������'B/�234<�&�I:34?& " 3 %% �� !;DD �% �I�B%�� �3/ 5�8�*8%���& �! "I&�?�:*K#"':�"

121002 Introduction to Computer Programming45

Page 46: chapter4_1

�+/� )�X �>*1!*$ �3 *1. �+����1�!$ >0!5 !&�&�9�:B% �!������'B/�234<34�I:34?&KB�K8� 5:;'B/�234

<�&�I:34?&2. �!�T2*3 / � (+��:B% �&�9, ���& �8��, ���&?��, M��, <9�3. 1��5M 3. 1��5M

J6�!1��5M �� ��� 0 J*+. �!�T2

Choise (+��:B% �&�9 char

Ans 'B/�234 float

Width ���& �8�� float

Long ���&?�� float

121002 Introduction to Computer Programming46

4. <& �! 'B/�234<34�I:34?&KB�K8� = �8�� * ?�� 'B/�234<�&�I:34?& = 0.5 * M�� * <9�

Base M�� float

High <9� Float

Page 47: chapter4_1

�>*1!*$ �3 *1. �!#4&(8� �!2�����2. 5<"�<=���&�9�:B% ���3. 07%��=�(+��:B% �&�9 (Choise)4. �:B% �!2�����"8�?���<+4� switch (Choise)

4.1 \8� Choise �0]� ^1_ AI82�����(�& :J=&���<+4� "+��3/ - 07%��=� Width, Long - 07%��=� Width, Long

- �������=� Area = Width * Long%% a02�����*8% 5

4.2 \8� Choise �0]� ^2_ AI82�����(�& :J=&���<+4� "+��3/ - 07%��=� Base, high

- �������=� Area = Base * high%% a02�����*8% 5

4.3 \8� Choise �0]� ^3_ AI82�����(�& :J=&���<+4� "+��3/

121002 Introduction to Computer Programming47

4.3 \8� Choise �0]� ^3_ AI82�����(�& :J=&���<+4� "+��3/ - %% �� <=�� �!2�����%% a02�����*8% 5

4.4 �% �I�B%�� �3/ '#&')*8%���&5�8�*8%K#"':�" %% a02�����*8% 5

5. <#/�<J" �!2�����

Page 48: chapter4_1

switch

start

5��5<���-

7m#��3� Choise

Case 1 Case 2 Case 1 Case 4switch(Choise)

�����6 Area=Width * Long

Case 1 Case 2 Case 1 Case 4

7m#��3� width,long

�����6 Area=Base * high

7m#��3� Base,high

121002 Introduction to Computer Programming48

Width * Long

end

5��5< Area

Base * high

5��5< Area 5��5< Area

Page 49: chapter4_1

#include <iostream.h>#include <conio.h>int main(){float Ans, Width, Long, Base, high;int Choise;

cout << "select Choise ==> ";cin >> Choise; cin >> Choise; cout << "\n";

switch(Choise) {case 1 :

cout << "Input Width : ";cin >> Width;

cout << "\n";

cout << "Input Long : ";

121002 Introduction to Computer Programming49

cout << "Input Long : ";cin >> Long;cout << "\n";

Ans = Width * Long;cout << "Ans ==> " << Ans << "\n"; break ;

Page 50: chapter4_1

case 2 :

cout << "Input Base : ";cin >> Base;cout << "\n";

cout << "Input high : ";cin >> high;cin >> high;cout << "\n";

Ans = 0.5 * Base * high;cout << "Ans ==> " << Ans << "\n"; break ;

case 3 :exit (0);

default :

121002 Introduction to Computer Programming50

default :cout << "Unknown clss \n" << Choise;

}

getch();return 0;

}