set and get functions

[fsufreak78]

Having a little trouble with the set and get functions, can anyone help me?


#include <string> // program uses C++ standard string class
using namespace std;

// Invoice class definition
class Invoice
{
public:
// constructor initializes the four data members
Invoice( string, string, int, int );

// set and get functions for the four data members
void setPartNumber( string ); // part number
string getPartNumber();

void setPartDescription( string ); // part description
string getPartDescription();

void setQuantity( int ); // quantity
int getQuantity();

void setPricePerItem( int ); // price per item
int getPricePerItem();

// calculates invoice amount by multiplying quantity x price per item
int getInvoiceAmount();

private:
string partNumber; // the number of the part being sold
string partDescription; // description of the part being sold
int quantity; // how many of the items are being sold
int pricePerItem; // price per item

}; // end class Invoice






#include <iostream>
#include "Invoice.h"
using namespace std;

// function main begins program execution
int main()
{
// create an Invoice object
Invoice invoice( "12345", "Hammer", 100, 5 );

// display the invoice data members and calculate the amount
cout << "Part number: " << invoice.getPartNumber() << endl;
cout << "Part description: " << invoice.getPartDescription() << endl;
cout << "Quantity: " << invoice.getQuantity() << endl;
cout << "Price per item: $" << invoice.getPricePerItem() << endl;
cout << "Invoice amount: $" << invoice.getInvoiceAmount() << endl;

// modify the invoice data members
invoice.setPartNumber( "123456" );
invoice.setPartDescription( "Saw" );
invoice.setQuantity( -5 ); // negative quantity, so quantity set to 0
invoice.setPricePerItem( 10 );
cout << "\nInvoice data members modified.\n\n";

// display the modified invoice data members and calculate new amount
cout << "Part number: " << invoice.getPartNumber() << endl;
cout << "Part description: " << invoice.getPartDescription() << endl;
cout << "Quantity: " << invoice.getQuantity() << endl;
cout << "Price per item: $" << invoice.getPricePerItem() << endl;
cout << "Invoice amount: $" << invoice.getInvoiceAmount() << endl;
} // end main





#include <iostream>
#include "Invoice.h"
using namespace std;

// Invoice constructor initializes the class's four data members
Invoice::Invoice( string number, string description, int count, int price )
{
setPartNumber( number ); // store partNumber
setPartDescription( description ); // store partDescription
setQuantity( count ); // validate and store quantity
setPricePerItem( price ); // validate and store pricePerItem
} // end Invoice constructor


// set part number
void Invoice::setPartNumber( string number )
{

[ need help here ] // no validation needed

} // end function setPartNumber


// get part number
string Invoice::getPartNumber()
{
[ need help here ]

} // end function getPartNumber


// set part description
void Invoice::setPartDescription( string description )
{
[need help here] // no validation needed

} // end function setPartDescription


// get part description
string Invoice::getPartDescription()
{
[ need help here ]

} // end function getPartDescription


// set quantity; if not positive, set to 0
void Invoice::setQuantity( int count )
{
[ need help here ]

} // end function setQuantity


// get quantity
int Invoice::getQuantity()
{
[ need help here ]

} // end function getQuantity


// set price per item; if not positive, set to 0
void Invoice::setPricePerItem( int price )
{
[ need help here ]

} // end function setPricePerItem


// get price per item
int Invoice::getPricePerItem()
{
[ need help here ]

} // end function getPricePerItem


// calulates invoice amount by multiplying quantity x price per item
int Invoice::getInvoiceAmount()
{
[ need help here ]

} // end function getInvoiceAmount

[Disch]

Pretty simple. Getters should return the appropriate variable. Setters should assign it to whatever was passed to the function (the parameter).

[fsufreak78]

Disch (6541) Dec 9, 2011 at 6:26pm
Pretty simple. Getters should return the appropriate variable. Setters should assign it to whatever was passed to the function (the parameter).

ya but im having trouble with knowing what i should put in the places like setpartnumber and getpartnumber, i understand what ur saying but the exact code i should place in there is the issue.

[Disch]

This is basic to the point where I can't really explain it without giving you the answer outright.

Have you worked with functions before? Do you know how to return variables? How to use parameters?

setPartNumber would assign the partNumber variable so that it matches the passed 'number' parameter

getPartNumber would return the partNumber variable.

That's really all it is. Each function is a simple 1-liner.

[Moschops]

Here's one example, adding a single lie to your code above. It's really this simple.

// get price per item
int Invoice::getPricePerItem()
{
return pricePerItem;

} // end function getPricePerItem 

[SIK]

ie.

// set part number
void Invoice::setPartNumber( string number )
{
   partnumber = number;

} // end function setPartNumber


// get part number
string Invoice::getPartNumber()
{
   return partnumber;

} // end function getPartNumber

As explained by Disch - this illustrates it for partnumber. The rest follows the same logic.

[SIK]

spelling correction:

// set part number
void Invoice::setPartNumber( string number )
{
   partNumber = number;

} // end function setPartNumber


// get part number
string Invoice::getPartNumber()
{
   return partNumber;

} // end function getPartNumber

[TAZO]

Here's another example of Mutators & Accessors.

class myClass{
public:
    myClass( string name, int age );
    void setmyName( string name );
    string getmyName() const;
    void setAge( int age );
    int getAge() const;
privates:
    string myName;
    int age;
}

int main (){
    myClass me;

    return 0;
}

myClass::myClass( string name, int age ): myName(name), age(age) {}
// it is always better to use initialization list in your cTor. also,
// by saying "age(age)" the compiler won't have problem understanding
// that the first one is the data member & the second one is the parameter
// passed (from right the left). Also when using initialization list, remember 
// to list them in the same order that they are defined.

void myClass::setmyName( string name ){
    myName = name;
}
// here we have a mutator method that sets the name of myClass.

string myClass::getmyName() const { return myName; }
// here we have an accessor method that returns type string for the 
// name of myClass.

void myClass::setAge( int age ){
    this->age = age;
}
// same as the first mutator method, but this time we need to point out 
// the difference between the two age datas. "this->age" is the data 
// member of my class. "age" is the parameter passed.

int myClass::getAge() const { return age; }
// same as the myName accessor, returning type int for the age of myClass. 

[ne555]

class Invoice{
public:
  string partNumber;
  string partDescription;
  int quantity;
  int pricePerItem;

[fsufreak78]

Thanks for all the help guys,I'm very new to programming so I'm still trying to get the basic stuff down.