Question

A grocery list is provided below: Create three different classes named Milk. Bread, and Eggs, where each has the following members: private data member "unit_price private data member "quantity". Default and overloaded constructors Provide properties for the private data members public total_price method which returns the total price (e.g., unit_price times quantity) A ToString() method that returns the info of the object Create a class named Grocery, which has the following members my_milk of type Milk my_bread of type Bread my_eggs of type Eggs An overloaded constructor which takes all the items above as inputs An expense method which calculates the total price of all items. This function must call the individual total_price methods reside in the classes Milk, Bread, and Eggs A ToString() function Develop a driver main function to demonstrate all of the above

Answer 1

Hi,

Just solved your problem as per your reuirement , please find the below code and also attached sample output.

I have wrriten the code in JAVA.

Milk.Java

public class Milk {

  
   private float item_price;
   private int quantity;
  
   //Default Constructor
   public Milk(){
          
       }
      
   //Parameterized constructor
   public Milk(float item_price, int quantity){
           this.item_price= item_price;
           this.quantity = quantity;
       }
  
   //setters and getters
   public float getItem_price() {
       return item_price;
   }
   public void setItem_price(float item_price) {
       this.item_price = item_price;
   }
   public int getQuantity() {
       return quantity;
   }
   public void setQuantity(int quantity) {
       this.quantity = quantity;
   }
   public float total_price(){
       return item_price*quantity;
   }
   @Override
   public String toString() {
       return "Milk [item_price=" + item_price + ", quantity=" + quantity + "]";
   }
  
   }

Bread.java

public class Bread {

  
   private float item_price;
   private int quantity;
  
   //Default constructor
  
   public Bread(){
          
       }
       //Parameterized constructor
   public Bread(float item_price,int quantity){
           this.item_price= item_price;
           this.quantity = quantity;
          
       }
   public float getItem_price() {
       return item_price;
   }
   public void setItem_price(float item_price) {
       this.item_price = item_price;
   }
   public int getQuantity() {
       return quantity;
   }
   public void setQuantity(int quantity) {
       this.quantity = quantity;
   }
   public float total_price(){
       return item_price*quantity;
   }
   @Override
   public String toString() {
       return "Milk [item_price=" + item_price + ", quantity=" + quantity + "]";
   }
  

}

Eggs.java

public class Eggs {

   private float item_price;
   private int quantity;
  
   //Default constructor
  
       public Eggs(){
              
           }
           //Parameterized constructor
       public Eggs(float item_price,int quantity){
               this.item_price= item_price;
               this.quantity = quantity;
              
           }
      
   public float getItem_price() {
       return item_price;
   }
   public void setItem_price(float item_price) {
       this.item_price = item_price;
   }
   public int getQuantity() {
       return quantity;
   }
   public void setQuantity(int quantity) {
       this.quantity = quantity;
   }
   public float total_price(){
       return item_price*quantity;
   }
   @Override
   public String toString() {
       return "Milk [item_price=" + item_price + ", quantity=" + quantity + "]";
   }
  

}

Grocery.java

public class Grocery {

  
   private Milk myMilk;
   private Bread myBread;
   private Eggs myEggs;
  
   public Grocery(Milk myMilk, Bread myBread, Eggs myEggs) {
      
       this.myMilk = myMilk;
       this.myBread = myBread;
       this.myEggs = myEggs;
   }
   public String toString(){
       System.out.println("Item \tUnit price \tQuantity");
       return "Milk \t$"+myMilk.getItem_price()+" \t\t"+myMilk.getQuantity()+
               "\nBread \t$"+myBread.getItem_price()+" \t\t"+myBread.getQuantity()+
               "\nEggs \t$"+myEggs.getItem_price()+" \t\t"+myEggs.getQuantity();
   }
   public void expense(){
      
       System.out.println("---------------------------------------------------");
       System.out.println("\nCalculating total price per individually item");
       System.out.println("\nItem \tTotal Price");
       System.out.println("Milk \t$"+myMilk.total_price());
       System.out.println("Bread \t$"+myBread.total_price());
       System.out.println("Eggs \t$"+myEggs.total_price());
      
       System.out.println("------------------------------------------------------");
       System.out.println("\nCalculating total expense including all items");
       System.out.println("Total Price \t$"+(myMilk.total_price()+myBread.total_price()+myEggs.total_price()));
      
   }
  
  

}

For demonstration of above written a Driver class

Driver.java

//Driver class to demonstrate functionality

public class Driver {

   public static void main(String[] args) {
       Milk milk = new Milk(3, 3);
       Bread bread = new Bread(4,6);
       Eggs eggs = new Eggs(5,9);
       Grocery gro = new Grocery(milk, bread, eggs);
       System.out.println(gro.toString());
       gro.expense();
   }

}

Output

Item Milk Bread $4.0 Eggs Unit price $3.0 Quantity $5.0 Calculating total price per individually item Total Price $9.0 Item Milk Bread $24.0 Eggs $45.0 Calculating total expense including all items Total Price $78.0

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