/*
Markup
Write a program that asks the user to enter item's wholesale cost and its markup
percentage. It should then display the item's retail price.  For example:
	* If an item's wholesale cost is 5.00 and its markup percentage is 100%. then
	  the item's retail price is 10.00.
	* If an item's wholesale cost is 5.00 and its markup percentage is 50%. then
	  the item's retail price is 7.50.
The program should have a function named calculateRetail that receives the wholesale
cost and the markup percentage as arguments, and returns the retail price of the item.
	  Input Validation: Do not accept negative values ofr either the wholesale cost
	  of the item or the percent markup.
*/
#include <iostream>
#include <iomanip>
using namespace std;

// function prototype
double calculateRetail();

int main()
{
	double RetalPrice;
	cout << "This program calculates and displays the retail price of an item.\n";
	RetalPrice = calculateRetail();
	cout << fixed << showpoint << setprecision(2);
	cout << "The retail price of the item is $" << RetalPrice <<endl;
	return 0;
}

/**********************************************************************
 *                          calculateRetail                           *
 * The function receives the wholesale cost and the markup percentage *
 * as arguments, and return the  retail price of the item             *
 **********************************************************************/
double calculateRetail()
{
	double Cost,
		   Markup;

    // Input Validation: only positive values for either the wholesale  
	// cost of the item or the percent markup.
	do
	{
		cout << "What is the item's wholesale cost? ";
		cin  >> Cost;
		if (Cost < 0)
		{
			cout << "Error!\n"
				 << "Wholesale cost must be a positive number.\n";
		}
	} while (!(Cost > 0));
	do
	{
		cout << "What is the item's markup percentage? ";
		cin  >> Markup;
		if (Markup < 0)
		{
			cout << "Error!\n"
				 << "The markup percentage must be a positive number.\n";	
		}
	} while (!(Markup > 0));

	Markup /= 100;
	return Cost * (1 + Markup);
}

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Read inputs from stdin

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

int main() 
{
    string name;
    cout << "Enter name:";
    getline (cin, name);
    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
}