121 lines
3.6 KiB
C++
121 lines
3.6 KiB
C++
// Lab 6 areas4.cpp
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// Program to calculate areas of objects
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// Llewellyn van der Merwe
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// INCLUDE ANY NEEDED FILES HERE.
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#include <iostream>
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using namespace std;
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// We set our globals
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// DEFINE THE NAMED CONSTANT PI HERE AND SET ITS VALUE TO 3.14159
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const float pi = 3.14159;
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// DECLARE ALL NEEDED VARIABLES HERE. GIVE EACH ONE A DESCRIPTIVE
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// NAME AND AN APPROPRIATE DATA TYPE.
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int choice = 0; // Menu choice should be 1, 2, 3, or 4
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float width; // used for both square and triangle
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float height; // used for both square and triangle
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float radius; // used for circle
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// Function prototypes
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void displayMenu();
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int getChoice(int min, int max);
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double findSquareArea();
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double findCircleArea();
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double findTriangleArea();
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int main()
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{
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// repeat the menu until quit
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do
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{
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// show the menu and set the choice
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displayMenu();
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// AND COMPUTE AND DISPLAY THE AREA FOR EACH VALID MENU CHOICE.
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// IF AN INVALID MENU CHOICE WAS ENTERED, AN ERROR MESSAGE SHOULD
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// BE DISPLAYED.
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if (choice == 1) {
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cout << "\nArea = " << findSquareArea() << "\n======================\n" << endl;
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} else if (choice == 2) {
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cout << "\nArea = " << findCircleArea() << "\n======================\n" << endl;
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} else if (choice == 3) {
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cout << "\nArea = " << findTriangleArea() << "\n======================\n" << endl;
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}
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} while (choice < 4);
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return 0;
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}
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// The menu function
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void displayMenu() {
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// WRITE STATEMENTS HERE TO DISPLAY THE 4 MENU CHOICES.
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cout << "Choose an object for which we should calculate the area for you. \n\n";
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cout << " 1 -- square\n" << " 2 -- circle\n"
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<< " 3 -- right triangle\n" << " 4 -- quit\n\n";
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// WRITE A STATEMENT HERE TO INPUT THE USER'S MENU CHOICE.
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cout << "Enter only a number: ";
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// get the choice
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choice = getChoice(1, 4);
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// USE AN IF/ELSE IF STATEMENT TO OBTAIN ANY NEEDED INPUT INFORMATION
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if (choice == 1 || choice == 3) {
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while (true) {
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cout << "Enter width: ";
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cin >> width;
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if (cin.fail()) {
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cin.clear();
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cin.ignore();
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cout << "\nError, must be a number\n" << endl;
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} else break;
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}
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while (true) {
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cout << "Enter height: ";
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cin >> height;
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if (cin.fail()) {
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cin.clear();
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cin.ignore();
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cout << "\nError, must be a number\n" << endl;
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} else break;
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}
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} else if (choice == 2) {
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while (true) {
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cout << "Enter radius of the circle: ";
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cin >> radius;
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if (cin.fail()) {
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cin.clear();
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cin.ignore();
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cout << "\nError, must be a number\n" << endl;
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} else break;
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}
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} else if (choice == 4) {
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return;
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}
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}
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/***** getChoice *****/
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int getChoice(int min, int max)
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{
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int input;
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// Get and validate the input
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cin >> input;
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while (cin.fail() || input < min || input > max)
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{ cout << "Invalid input. Enter an integer between " << min << " and " << max << ": ";
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cin >> input;
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}
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return input;
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}
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// calculate the square area
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double findSquareArea(){
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return width * height;
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}
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// calculate the circle area
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double findCircleArea(){
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return pi * radius * radius;
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}
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// calculate the triangle area
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double findTriangleArea(){
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return width * height;
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}
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