Jangsehyun final requirement

FINAL REQUIREMENT OF FUNDAMENTALS OF PRO-

GRAMMING AND DATABASE-THEORY AND APPLICATIONS

PROGRAMMING

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TOPICS IN PROGRAMMING


Looping

LoopingSwitch case


SWITCH CASE STATEMENT

In programming, a switch, case, select or inspect statement is a type of se-lection 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 Programming languages. Its purpose is to allow the value of a variable or expression to control the flow of program execution via a multway branch (or "go to", one of several labels). The main reasons for using a switch include improving 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.






SWITCH CASE STATEMENT 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). The basic format for using the switch case in the programming is outlined below. 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 switch-case statement is a multi-way decision statement. Un-like the multiple decision statement that can be created using if-else, the switch statement evaluates the conditional expression and tests it against numerous constant values. The branch corresponding to the value that the expression matches is taken during execution.




SWITCH CASE STATEMENT

Switch is used to choose a fragment of template de-pending on the value of an expression

This has a similar function as the If condition - but it is more useful in situations when there is many pos-sible values for the variable. Switch will evaluate one of several statements, depending on the value of a given variable. If no given value matches the vari-able, the default statement is executed.

The value of the expressions in a switch-case state-ment must be an ordinal type i.e. integer, char, short, long, etc. Float and double are not allowed.




Example of switch case IN C PROGRAMMING

#include <iostream>

#include <stdlib.h>

using namespace std;

void welcome();

char getChar();

void displayResponse(char choice);

int main(int argc, char *argv[])

{

char choice; // declares the choice variable

welcome(); // This calls the welcome function

choice = getChar(); // calls getChar and returns the value for choice

displayResponse(choice); // passes choice to displayResponse function

system("PAUSE");

return 0;

} // end main

// welcome function displays an opening message to

// explain the program to the user

void welcome()

{

cout << "This program displays different messages depending\n";

cout << "on which letter is entered by the user.\n";

cout << "Pick a letter a, b, c or d to see what\n";

cout << "the program will say.\n\n";

} // end of welcome function

// getChar asks the user for a letter a, b or c.

// The character is returned to where the function was called.

char getChar()

{

char response; // declares variable called response

cout << "Please type a letter a, b, c and d: "; // prompt for letter

cin >> response; // gets input from user and assigns it to response

return response; // sends back the response value

} // end getChar function

// displayResponse function takes the char variable and uses it

// to determine which set of tasks will be performed.

void displayResponse(char choice)

{

char again;


// switch statement based on the choice variable

switch (choice) // notice no semicolon

{

case 'A': // choice was the letter A

case 'a': // choice was the letter a

cout << "your awesome dude.\n\\n";

break; // this ends the statements for case A/a

case 'B': // choice was the letter b

case 'b': // choice was the letter b

cout << "you will find your lovelife.\n\n";

break; // this ends the statements for case B/b

case 'C': // choice was the letter C

case 'c': // choice was the letter c

cout << "your will won the lottery.\n\n";

break; // this ends the statements for case C/c

case 'D': // choice was the letter D

case 'd': // choice was the letter d

cout << "your so ugly!!.\n\n";

break; // this ends the statements for case D/d

default: // used when choice falls out of the cases covered above

cout << "You didn't pick a letter a, b or c.\n\n";

again = getChar(); // gives the user another try

displayResponse(again); // recalls displayResponse with new character

break;

} // end of switch statement

} // end displayResponse function


Running switch case IN C PROGRAMMING



LOOPING


There may be a situation when you need to execute a block of code several number of times. In general statements are executed sequentially: The first statement in a function is executed first, followed by the second, and so on.

Programming languages provide various control structures that allow for more complicated execution paths.A loop statement allows us to execute a statement or group of statements multiple times and following is the general from of a loop statement in most of the programming languages.




LOOPING


FOR LOOP

WHILELOOP

DO WHILE LOOP

C++ programming language provides following types of loop to handle looping requirements:


FOR LOOP A for loop is a repetition control structure that

allows you to efficiently write a loop that needs to execute a specific number of times.

The statements in the for loop repeat continu-ously for a specific number of times. The while and do-while loops repeat until a certain condition is met. The for loop repeats until a specific count is met. Use a for loop when the number of repetition is know, or can be supplied by the user.


#include <iostream>#include <cmath>using namespace std;

//prototypeint fallingdistance();

//main functionint main(){

int count = 1 ;int time;double distance ;cout << "Please enter time in 1

through 10 seconds.\n\n";

time = fallingdistance();

while ( time < 1 || time > 10){ cout << "Must enter between 1

and 10 seconds, please re-enter.\n"; time = fallingdistance();

}

cout <<"\nSecondsfalling distance\n";cout <<"---------------------------------------\n";

for ( count = 1; count <= time; count++){

distance = .5 * 9.8 * pow(time, 2.0);

cout << count << " " << distance <<" meters"<< endl;

} system ("pause");

return 0;}// falling distance function for a return value in seconds transfer to timeint fallingdistance (){

int seconds;cin >> seconds;return seconds;

}

EXAMPLE OF FOR LOOPING IN C PROGRAMMING



RUNNING FOR LOOP IN IN C PROGRAMMING



WHILE LOOP The while loop allows programs to repeat

a statement or series of statements, over and over, as long as a certain test condi-tion is true.

The while loop can be used if you don’t know how many times a loop must run.

A while loop statement repeatedly exe-cutes a target statement as long as a given condition is true.



EXAMPLE OF WHILE LOOP IN C PROGRAMMING

#include <iostream.h>

int main(void) {

int x = 0;

int y = 0;

bool validNumber = false;

while (validNumber == false) {

cout << "Please enter an integer between 1 and 10: ";

cin >> x;

cout << "You entered: " << x << endl << endl;

if ((x < 1) || (x > 10)) {

cout << "Your value for x is not between 1 and 10!"

<< endl;

cout << "Please re-enter the number!" << endl << endl;

}

else

validNumber = true;

}

cout << "Thank you for entering a valid number!" << endl;

return 0; }



RUNNING WHILE LOOP IN C PROGRAMMING



DO WHILE LOOP

In most computer programming languages, a do while loop, sometimes just called a while loop, is a control flow statement that allows code to be executed once based on a given Boolean condition.

The do while construct consists of a process symbol 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. Contrast with the while loop, which tests the condition before the code within the block is executed.



DO WHILE LOOP

Unlike for and while loops, which test the loop condition at the top of the loop, the do...while loop checks its condition at the bottom of the loop.

A do...while loop is similar to a while loop, except that a do...while loop is guaranteed to execute at least one time.

The do-while loop is similar to the while loop, ex-cept that the test condition occurs at the end of the loop. Having the test condition at the end, guaran-tees that the body of the loop always executes at least one time.


EXAMPLE OF A DO WHILE LOOP IN C PROGRAMMING

#include <iostream> using namespace std; main() { int num1, num2; char again = 'y';

while (again == 'y' || again == 'Y') { cout << "Enter a number: "; cin >> num1; cout << "Enter another number: "; cin >> num2; cout << "Their sum is " << (num1 + num2) << endl; cout << "Do you want to do this again? "; cin >> again; } return 0; }



RUNNING DO WHILE LOOP IN C PROGRAMMING




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Present this final re-quirement to profes-sor Erwin Globio


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Jangsehyun final requirement