Question

4G,盃29% 7:26 Expert Q&A Create a java program which will prompt a user to input a product and its cost. Using a while loop that will run until the sentinel value of "stop" (any case) is entered, the program will look for items with a cost greater than or equal to $100.00. The program will find the average cost of those items. Note: immediately after your statement containing input.nextDouble) you will need to add the following input.nextLine) statement. This will cause the input scanner to consume the newline after your

This question has already been answered however I do not understand the particulars of the answer. for an example why are we importing an average class I thought that we could solve the problem just inputting the scanner and doing the import command at the top. Also at the bottom of the problem they increment the counter I thought you increment the counter at the top. Is there any way someone could do a detailed step-by-step explanation of the actual program? For your own interest the question-and-answer have already been posted so I don't think there's any need to do an actual solution but you could cut and paste the solution and explain it step-by-step

Answer 1

I had tried to simply the solution .All your Doubts will be solved and is easy than previous answers you had seen.

List - It is Collection class which is similar to array , but the only difference is the worry about the size of list is not there, i.e size is not fixed like array.

Program :-

import java.util.*;   
import java.util.Scanner.*;

class HomeworkLib1
{
   public static void main(String[] args) // Main method
   {

// Declaration of variables
       int i;
       double sum=0;
       Scanner sc1=new Scanner(System.in); // Create Scanner object for String input
       Scanner sc2=new Scanner(System.in); // Create Scanner object for Double input
       Scanner sc3=new Scanner(System.in); // Create Scanner object for Integer input

       List<Double> l1=new ArrayList<Double>(); // Creating a List

       while(true) // Start of while
       {
           System.out.println("Enter 1) Enter Details of Another Product \n 2) Exit"); // Ask User for Choice
           int n=sc3.nextInt(); // Scan the choice and store it in n

           switch(n) // Start of Switch
           {
               case 1:
               {
                   System.out.println("Enter the Cost of the Product"); // Ask User for Cost
                   double cost=sc2.nextDouble(); // Scan the input and store it in cost
                   if(cost>=100) // Check if cost is Greater than or equal to 100
                   {
                       l1.add(cost); // Add the cost of the Product to the List
                       System.out.println("Enter Product Name"); // Ask for Product name
                       String product=sc1.nextLine(); // Scan the input and store it in product variable
                   }// end of if
                   else
                   {
                       System.out.println("Cost Less Than 100"); // if cost is less than 100 print the message
                   }// end of else
                   break; // break the switch case loop
               } // end of case 1

               case 2: // User don't want to add other product
               {
                   break; // break the switch case loop
               } end of case 2

               default: // if choice is not valid ,by default this case is executed
               {
                   System.out.println("Invalid Entry");
               } // end of default

           } // end of switch

           if(n==2){ // If the user don't want to add another product
               break; // break from while loop
           } // end of if

       }// end of while

       for(i=0;i<l1.size();i++) // loop to calculate average of product Cost
       {
           sum=sum + l1.get(i); // l1.get(i) will get the element from list at index i and will add it to sum
       } // end of for

       System.out.println("Average of Cost is :$" +sum); // print the Average of cost

   } // end of main method

} // end of class

Answer 2

Solution:

I have given line by line explanation by giving commenting line in the program. In case of any problem please do the comment.

//import java.util package to use Scanner class to take user input

import java.util.*;

//class definition

class AverageProductCost

{

public static void main(String args[])

{

Scanner sc = new Scanner(System.in); //Scanner class for taking input

String product_name; //declare product_name

double product_cost, average; //declare product_cost and average

double total = 0.0; //declare total to find the total cost of all product whose cost is >= 100

int count = 0; //declare count to keep track of entered products whose cost is greater than or equal to $100

//infinite while loop that break only when user enters stop

while(true)

{

//prompt the user to input product name

System.out.println("Enter product name:");

product_name = sc.nextLine();

//break the loop when user enters the string stop

if(product_name.equalsIgnoreCase("stop"))

{

break;

}

//prompt the user to input product cost

System.out.println("Enter product cost:");

product_cost = sc.nextDouble();

//consume newline

sc.nextLine();

//condition to check product cost >= 100 or not

if(product_cost >= 100)

{

//if condition is true then add the product cost to total to find total cost

total = total + product_cost;

//increase count whenever the product cost is >= 100

//note: we didn't increase the count at the top because we have to increase the count only when cost is >= 100

count++;

}

}

//calculate the average by dividing the total cost by count(total product whose cost is >= 100)

average = total/count;

//print average of the product cost

System.out.println("Average cost of the items is: "+average);

}

}

Please give thumnbsup, if you like it. Thanks.