Switch case and looping jam

A programming language is used to write
computer programs such as application and utilities.

Programming allows a programmer or end user to
develop the sets of instructions that constitute a
computer program or software. 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.
Fundamentally programs manipulate numbers and text.
These are the building blocks of all programs.
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).


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
3 loop control components:
-initialization of the loop control variable
-test of the loop repetition condition
-change (update) of the loop control variable

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
•Both the for statement and the while statement evaluate a loop
repetition condition before the first execution of the loop body.

•In most cases, this pretest is desirable and prevents the loop from
executing when there may be no data items to process or when the
initial value of the loop control variable is outside the expected range.

•There are some situations, generally involving interactive input,
when we know that a loop must execute at least one time.

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 STATEMENT 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.


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.


Submitted to:
Prof. Erwin Globio

Submitted by:
Unite, Jamaica Aubrey T.
BM10203


Switch case and looping jam

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