Switch case looping

We first define the word “programming”, it is a
computer language programmers use to develop
applications, scripts, or other set of instructions for a
computer to execute.
programming is instructing a computer to do
something for you with the help of a programming
language. The role of a programming language can be
described in two ways:
 Technical: It is a means for instructing a Computer to
perform Tasks
 Conceptual: It is a framework within which we organize
our ideas about things and processes.
http://eglobiotraining.com

As an individual, I have learned that
programming is a very broad because it composes
many scripts, applications and can be used to run a
program that has been part of the programming
language.
A programming language should both
provide means to describe primitive data and
procedures and means to combine and abstract
those into more complex ones.


The distinction between data and
procedures is not that clear cut. In many
programming languages, procedures can be
passed as data (to be applied to ``real'' data)
and sometimes processed like ``ordinary'' data.
Conversely ``ordinary'' data can be turned into
procedures by an evaluation mechanism.


At first, programming is confusing because
you have so much to understand about codes that
will enable to run a program. Programming has
applications and program development, the best
example for this is the Internet bowser…
Programming is a creative process done by
programmers to instruct a computer on how to do
a task. Programming languages let you use them in
different ways, e.g adding numbers, etc… or
storing data on disk for later retrieval.


You have to consider languages to run or write
your own program, most demanded language in
programming is the DEV C++ (a full-featured Integrated
Development Environment (IDE)).

C++ is one of the most used programming
languages in the world. Also known as "C with Classes".

New to programming or thinking about it? It might
surprise you to know that there are many programmers
who program just for fun and it can lead to a job.


Switch case statements are a substitute for long if
statements that compare a variable to several "integral"
values ("integral" values are simply values that can be
expressed as an integer, such as the value of a char). –
A switch, case, select or inspect statement is a type of
selection control mechanism that exists in
most imperative programming languages such as Pascal,
Ada, C/C++, C#, Java, and so on. It is also included in
several other types of languages. Its purpose is to allow
the value of a variable or expression to control the flow of
program execution via a multiway branch (or "goto", one
of several labels).


 - To improve clarity, by reducing otherwise
repetitive coding, and (if the heuristics permit) also
offering the potential for faster execution through
easier compiler optimization in many cases.


1. The If – else Statement

-The if statement allows the programmer to make
decisions within a program.
- The general format of an if statement is:
If (expression)
statement
-Where expression represents a relational, equality, or
logical expression ( conditional expression) .


If statement (two alternatives)
Form:
If (condition) Note: if condition evaluates to true, then statement is
statement; executed and statement is skipped; otherwise, statement is
else skipped and statement is executed
statement;

If statement (One-Alternatives)
Form:
If (condition) Note: if condition evaluates to true, then statement is
statement; executed and statement is skipped

Format of the if statement
- All if statement examples in this text indent statements. The word else
Is typed without indention on a separate line. The format of the if statement
makes its meaning apparent and is used solely to improve program readability;
The format makes no difference to the computer


 If we know how to write a C expression that is equivalent of a
question such as “Is resting the value of expression to select a
course of action. In C, the statement is the primary selection control
structure
 Me: it’s hard to write c expression. So, I just copy and paste it into
internet.
 A programming language is an artificial language designed to
communicate instructions to a machine, particularly a computer.
Programming languages can be used to create programs that
control the behavior of a machine and/or to
express algorithms precisely.


 1. Open Dev C++
 2. Click File and choose New
 3. Post your Statements
 4. after you post your statement
 5. Save it .choose file and save or
 6. click f9 or you can see it shaped like a
square

http://eglobiotraining.com/

basic format for using switch case:

switch ( <variable> ) {
case this-value:
Code to execute if <variable> == this-value
break;
case that-value:
Code to execute if <variable> == that-value
break;
...
default:
Code to execute if <variable> does not equal the value following any of the
cases
break;
}

The value of the variable given into switch is compared to the value following each
of the cases, and when one value matches the value of the variable, the computer
continues executing the program from that point.


The condition of a switch statement is a
value. The case says that if it has the value of
whatever is after that case then do whatever follows
the colon.


The break is used to break out of the case
statements. An important thing to note about the
switch statement is that the case values may only be
constant integral expressions.


Break is a keyword that breaks out of the
code block, usually surrounded by braces, which
it is in. In this case, break prevents the program
from falling through and executing the code in
all the other case statements.


The default case is optional, but it is wise to
include it as it handles any unexpected cases. Switch
statements serves as a simple way to write long if
statements when the requirements are met. Often
it can be used to process input from a user.


This shows how would you use a Switch in a Program
#include <iostream>

using namespace std;

void playgame()
{
cout << "Play game called";
}
void loadgame()
}
cout << "Load game called";
void playmultiplayer()
{
cout << "Play multiplayer game called";
}

int main()
{
int input;

cout<<"1. Play gamen";
cout<<"2. Load gamen";
cout<<"3. Play multiplayern";
cout<<"4. Exitn";
cout<<"Selection: "; cin>> input;
switch ( input ) {
case 1: // Note the colon, not a semicolon
playgame();
break;
loadgame();
break;
playmultiplayer();
break;
cout<<"Thank you for playing!n";
break;
default: // Note the colon, not a semicolon
cout<<"Error, bad input, quittingn";
break;
}
cin.get();
}

That program will compile, but cannot be run until the
undefined functions are given bodies, but it serves as a
model (albeit simple) for processing input. If you do not
understand this then try mentally putting in if statements for
the case statements. Default simply skips out of the switch
case construction and allows the program to terminate
naturally. If you do not like that, then you can make a loop
around the whole thing to have it wait for valid input. You
could easily make a few small functions if you wish to test
the code.


Loops are used to repeat a block of code.
Being able to have your program repeatedly
execute a block of code is one of the most basic
but useful tasks in programming -- many
programs or websites that produce extremely
complex output (such as a message board) are
really only executing a single task many times.


(They may be executing a small number of
tasks, but in principle, to produce a list of
messages only requires repeating the operation
of reading in some data and displaying it.) Now,
think about what this means: a loop lets you
write a very simple statement to produce a
significantly greater result simply by repetition.


One Caveat: before going further, you should understand
the concept of C++'s true and false, because it will be
necessary when working with loops (the conditions are the
same as with if statements).

Three types of Loops:
for, while, and do..


FOR

For ( variable initialization; condition; variable update ) {
Code to execute while the condition is true
}


The variable initialization allows you to either declare a
variable and give it a value or give a value to an already existing
variable. Second, the condition tells the program that while the
conditional expression is true the loop should continue to repeat
itself. The variable update section is the easiest way for a for loop
to handle changing of the variable. It is possible to do things like
x++, x = x + 10, or even x = random ( 5 ), and if you really wanted to,
you could call other functions that do nothing to the variable but
still have a useful effect on the code.
Notice that a semicolon separates each of these sections, that is
important. Also note that every single one of the sections may be
empty, though the semicolons still have to be there. If the
condition is empty, it is evaluated as true and the loop will repeat
until something else stops it.


Example:

#include <iostream>

using namespace std; // So the program can see cout and endl

int main()
{
// The loop goes while x < 10, and x increases by one every loop
for ( int x = 0; x < 10; x++ ) {
// Keep in mind that the loop condition checks
// the conditional statement before it loops again.
// consequently, when x equals 10 the loop breaks.
// x is updated before the condition is checked.
cout<< x <<endl;
}
cin.get();
}

This program is a very simple example of a for loop. x is set to zero,
while x is less than 10 it calls cout<< x <<endl; and it adds 1 to x until the
condition is met. Keep in mind also that the variable is incremented
after the code in the loop is run for the first time.


WHILE
The basic structure:
While ( condition ) { Code to execute while the condition is true }
The true represents a boolean expression which could be x == 1
or while ( x != 7 ) (x does not equal 7). It can be any combination
of boolean statements that are legal. Even, (while x ==5 || v == 7)
which says execute the code while x equals five or while v equals
7. Notice that a while loop is the same as a for loop without the
initialization and update sections. However, an empty condition
is not legal for a while loop as it is with a for loop.


Example:

#include <iostream>

using namespace std; // So we can see cout and endl

int main()
{
int x = 0; // Don't forget to declare variables

while ( x < 10 ) { // While x is less than 10
cout<< x <<endl;
x++; // Update x so the condition can be met eventually
}
cin.get();
}

The easiest way to think of the loop is that when it reaches the brace at the
end it jumps back up to the beginning of the loop, which checks the condition
again and decides whether to repeat the block another time, or stop and
move to the next statement after the block.


DO..WHILE

are useful for things that want to loop at least once.

The Structure:
do {
} while ( condition ) ;


Notice that the condition is tested at the end of the block
instead of the beginning, so the block will be executed at
least once. If the condition is true, we jump back to the
beginning of the block and execute it again. A do..while loop
is basically a reversed while loop. A while loop says "Loop
while the condition is true, and execute this block of code", a
do..while loop says "Execute this block of code, and loop
while the condition is true".


Example:

#include <iostream>


int main()
{
int x;

x = 0;
do {
// "Hello, world!" is printed at least one time
// even though the condition is false
cout<<"Hello, world!n";
} while ( x != 0 );
cin.get();
}

Keep in mind that you must include a trailing semi-colon after the while in the
above example. A common error is to forget that a do..while loop must be
terminated with a semicolon (the other loops should not be terminated with a
semicolon, adding to the confusion). Notice that this loop will execute once,
because it automatically executes before checking the condition.


LOOPING STATEMENT 1
#include <iostream>

int main()
{

// nSelection must be declared outside do/while loop
int nSelection;

do
{
cout << "Please make a selection: " << endl;
cout << "1) Addition" << endl;
cout << "2) Subtraction" << endl;
cout << "3) Multiplication" << endl;
cout << "4) Division" << endl;
cin >> nSelection;
} while (nSelection != 1 && nSelection != 2 &&
nSelection != 3 && nSelection != 4);

// do something with nSelection here
// such as a switch statement

return 0;
}


LOOPING STAEMENT 2
#include <iostream>
int main()
{
int nSelection;
double var1, var2;

do
{
cin >> nSelection;
}

while (nSelection != 1 && nSelection != 2 &&
nSelection != 3 && nSelection != 4);

if (nSelection == 1)
{
cout << "Please enter the first whole number ";
cin >> var1;
cout << "Please enter the second whole number ";
cin >> var2;
cout << "The result is " << (var1+var2) << endl;
}


LOOPING STATEMENT 3
{
cin >> var1;
cin >> var2;
cout << "The result is " << (var1-var2) << endl;
}
{
cin >> var1;
cin >> var2;
cout << "The result is " << (var1*var2) << endl;
}
{
cin >> var1;
cin >> var2;
cout << "The result is " << (var1/var2) << endl;
}

return 0;
}


LOOPING STATEMENT 3
#include <iostream>
int main()
{
int nSelection;
double var1, var2;
while (1)
{
do
{
cout << "5) Exit" << endl;
cin >> nSelection;
} while (nSelection != 1 && nSelection != 2 &&
nSelection != 3 && nSelection != 4 &&
nSelection != 5);

{
cin >> var1;
cin >> var2;
cout << "The result is " << (var1+var2) << endl;
}


LOOPING STATEMENT 4
else if (nSelection == 2)
{
cin >> var1;
cin >> var2;
cout << "The result is " << (var1-var2) << endl;
}
{
cin >> var1;
cin >> var2;
cout << "The result is " << (var1*var2) << endl;
}
{
cin >> var1;
cin >> var2;
cout << "The result is " << (var1/var2) << endl;
}
else
{
return 0;
}
}
}


LOOPING STATEMENT 5
#include <iostream>

using namespace std; // So the program can see cout and endl

int main()
{
// The loop goes while x < 10, and x increases by one every loop
for ( int x = 0; x < 10; x++ ) {
// Keep in mind that the loop condition checks
// the conditional statement before it loops again.
// consequently, when x equals 10 the loop breaks.
// x is updated before the condition is checked.
cout<< x <<endl;
}
cin.get();
}


LOOPING STATEMENT 6
#include <iostream>


int main()
{
int x;

x = 0;
do {
// "Hello, world!" is printed at least one time
// even though the condition is false
cout<<"Hello, world!n";
} while ( x != 0 );
cin.get();
}


LOOPING STATEMENT 7
#include <iostream>

int main ()
{
int n;
cout << "Enter the starting number > ";
cin >> n;

while (n>0) {
cout << n << ", ";
--n;
}

cout << "FIRE!n";
return 0;
}


SWITCH CASE 1

SWITCH CASE
#include <iostream>


int main ()

{

int score;

cout << "What was your score?";

cin >> score;

if (score <= 25)

{

cout << "nOuch, less than 25...!";

}


SWITCH CASE 2
else if (score <= 50)

{

cout << "nYou score aint great mate..";

}


{

cout << "nYour pretty good, wel done man!";

}


{

cout << "nYou got to the top!!!";

}


SWITCH CASE 3
else

{

cout << "nYou cant score higher than 100!!! Cheater!!!!";

}

cin.ignore();

cin.get();

return 0;

}


SWITCH CASE 4

#include <iostream>


int main(){
cout << "Enter a number between 1 and 5!" << endl;
int number;
cin >> number;
if(number == 1){
cout << "one";
}
else if(number == 2){
cout << "two";
}
cout << "three";
}
cout << "four";
}
cout << "five";
}
else{
cout << number << " is not between 1 and 5!";
}
cout << endl;
system("pause");
}


SWITCH CASE 5
#include <iostream>
int main()
{
int price_before_discount, RM, dozen, total_price;

cout<< "How much is the price before discount for 1 dozen boxes of tissue?n";
cout<<"RM ";
cin>>price_before_discount;
cout<<"nn";

cout<< "How many dozen boxes of tissue you buy?n";
cin>>dozen;
cout<<"nn";

switch (dozen)
{
total_price = ((price_before_discount*dozen) * (95/100));
case '1': cout<< "Total price is RM ";
cout<<RM;
cout<<"nn";
break;

cout<<RM;
cout<<"nn";
break;

cout<<RM;
cout<<"nn";
break;

case '4' : cout<< "Total price is RM ";
cout<<RM;
cout<<"nn";
break;

default : cout<< "Total price is RM ";
cout<<RM;
cout<<"nn";
}

return 0;
}


SWITCH CASE 6
#include <stdlib.h>
#include <stdio.h>

int main(void) {
int n;
printf("Please enter a number: ");
scanf("%d", &n);
switch (n) {
case 1: {
printf("n is equal to 1!n");
break;
}
case 2: {
break;
}
case 3: {
break;
}
default: {
printf("n isn't equal to 1, 2, or 3.n");
break;
}
}
system("PAUSE");
return 0;
}


SWITCH CASE 7
#include <iostream>
int main(void)
{
char grade;
cout << "Enter your grade: ";
cin >> grade;
switch (grade)
{
case 'A':
cout << "Your average must be between 90 - 100"
<< endl;
break;
case 'B':
<< endl;
break;
case 'C':
<< endl;
break;
case 'D':
<< endl;
break;
default:
cout << "Your average must be below 60" << endl;
}
return 0;
}


In this looping statement, I used “while” looping, and I choose to show MDAS
just as an example for the program to run. If logical Expression evaluates
to true, the statement executes. The logical Expression is reevaluated. The
body of the loop continues to execute until the logicalExpression is false


I have came up with this by just starting to write this code: #include
<iostream> and then enter the succeeding codes, compiled and run.


I noticed that sometimes if the program does not run, it is because
some braces are not included and I accidentally put braces on the same
line and it causes the program not to read its contents. Programming is
sensitive, when there is missing variable or braces or some words it
does not run.


When I learned that programming is very sensitive and at the same
time very detailed when it comes to entering codes, I make sure
that it is clear means that I put everything important codes in it so
that the program would run.


So much codes that should be entered that even the spaces are needed
programming is very specific that whatever you have entered in to it you
should specify because when the statement is false it wouldn’t let you run
the program, I have experienced it before I arrived at this result.


Because of so many experiences I had before this program run, I found
programming is also interesting for the more you are practicing to
make a program run, the more questions that came up in my mind and
try something that will fit to this or entering new codes to make matrix
etc… that I know is possible.


In this switch case missing out a break statement causes control to fall
through to the next case label. Switches can always be replaced by
nested if-else statements, but in some cases this may be more clumsy.
Each break statement terminates the enclosing switch statement. Control
flow continues with the first statement


Unlike if-then and if-then-else statements, the switch statement can have a
number of possible execution paths, A switch works with the byte, short,
char, and int primitive data types.


The switch statement evaluates its expression, then executes all
statements that follow the matching case label.


The switch statement can include any number of case instances, but no
two case constants within the same switch statement can have the same
value. Execution of the statement body begins at the selected statement
and proceeds until the jump-statement transfers control out of
the case body.


USERNAME : Chem Batallones


Submitted by:
Batallones, Cherimay C.
BM10203


Switch case looping

More Related Content

What's hot

Viewers also liked

Similar to Switch case looping

Switch case looping