//  program will calculate area of shapes
//  9/14/21
//  Charles I Montanan IV

#include <iostream>
#include <iomanip>
#include <math.h>
using namespace std;

int main() 
{
    //displaying menu optionsn and title of program
    cout << "Architect Area Calcualtor: \n**************************" << endl;
    cout << "1.   Rectangle\n2.   Triangle\n3.   Circle\n4.   Quit" << endl;
    
    //defined my constants 
    double menu_item        =0;
    const int RECTANGLE  =1;
    const int TRIANGLE   =2;
    const int CIRCLE     =3;
    const int QUIT       =4;

    
    
    //displaying menu
    cout << "Please enter a menu item (1-4) \n\n"; 
    cin >> menu_item;
      
    //validatiing the input 1-4 rough af, i couldnt get it perfect
    if (!(menu_item==1.0||menu_item==2.0||menu_item==3.0||menu_item==4.0))
    {
        cout << "Invalid Input";
        return 0;
    }
    
    //casting menu_item to switch
    switch ((int)menu_item)
    {
      //reading shape dimensions, validating dimensions and calculating area for different shapes 
      case RECTANGLE:
          cout << "Rectangle";
          cout << "\nPlease enter the length > ";
          double length;
          cin >> length;
          cout << "\nPlease enter the width > ";
          double width;
          cin >> width;
          cout.precision(2);
          cout << "\n\n Area = " << fixed << length*width << " sq/ft" <<endl;
                break;
          
      case TRIANGLE:
          cout << "Triangle";
          cout << "\nPlease enter the base > ";
          double base;
          cin >> base;
          cout << "\nPlease enter the height > ";
          double height;
          cin >> height;
          cout.precision(2);
          cout << "\n\n Area = " << fixed << base*height/2 << " sq/ft" <<endl;
                break;
                
      case CIRCLE: cout << "Circle";
          cout << "\nPlease enter the radius > ";
          double radius;
          cin >> radius;
          cout.precision(2);
          cout << "\n\n Area = " << fixed << radius*radius*M_PI << " sq/ft" <<endl;
                break;
                
      case QUIT: cout << "Goodbye, come again soon." << endl;
                break;
      default: cout << "Invalid Input";
                            return 0;
    }
    
}
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#include <iostream>
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    cout << "Enter name:";
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    cout << "Hello " << name;
    return 0;
}

About C++

C++ is a widely used middle-level programming language.

  • Supports different platforms like Windows, various Linux flavours, MacOS etc
  • C++ supports OOPS concepts like Inheritance, Polymorphism, Encapsulation and Abstraction.
  • Case-sensitive
  • C++ is a compiler based language
  • C++ supports structured programming language
  • C++ provides alot of inbuilt functions and also supports dynamic memory allocation.
  • Like C, C++ also allows you to play with memory using Pointers.

Syntax help

Loops

1. If-Else:

When ever you want to perform a set of operations based on a condition If-Else is used.

if(conditional-expression) {
   //code
}
else {
   //code
}

You can also use if-else for nested Ifs and If-Else-If ladder when multiple conditions are to be performed on a single variable.

2. Switch:

Switch is an alternative to If-Else-If ladder.

switch(conditional-expression){    
case value1:    
 // code    
 break;  // optional  
case value2:    
 // code    
 break;  // optional  
......    
    
default:     
 code to be executed when all the above cases are not matched;    
}

3. For:

For loop is used to iterate a set of statements based on a condition.

for(Initialization; Condition; Increment/decrement){  
  //code  
}

4. While:

While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.

while (condition) {  
// code 
}

5. Do-While:

Do-while is also used to iterate a set of statements based on a condition. It is mostly used when you need to execute the statements atleast once.

do {  
 // code 
} while (condition);

Functions

Function is a sub-routine which contains set of statements. Usually functions are written when multiple calls are required to same set of statements which increases re-usuability and modularity. Function gets run only when it is called.

How to declare a Function:

return_type function_name(parameters);

How to call a Function:

function_name (parameters)

How to define a Function:

return_type function_name(parameters) {  
 // code
}