Method exercises with input parameters, return values and test cases:

Simpler Method exercises with input parameters, return values and test cases:

Goal: create a method that returns a value and takes in a parameter. Use that method in a main routine. Create another method in the same class and use it in the same main routine. Then, add in user interaction. Then, use that method in a loop. Then accumulate some total inside the loop and print it at the end.

Create the following method:

Step I - create this method:

profitOnOneSale

Input parameters:
	Double	Price
	Double	Cost
Description of processing: The profit is the price minus the cost.
Return:
	Double	Profit

Now test this method:

When you are done, run just the profitOnOneSale method in BlueJ passing it a price of 100.02 and cost of 10.01 and see 90.01 returned.

Try again with a price of 30 and a cost of 100 and see -70 returned.

(If you do not get the right answer, try debugging with the stop sign in the margin of the BlueJ code)

Step II - code your main method to use this new method you created:

Put the following in your main method:

Create a variable myprice and set it to 100

Create a variable mycost and set it to 70

Create a variable myprofit;

Calculate the profit of the myprice and mycost variables. (For this exercise, you must use your profitOnOneSale method to do that. )

call the profitOnOneSale method sending the price and cost. Be sure to save the answer into a variable.

Tell the user : "Each time you sell your item at a price of " + myprice + " and a cost of " + mycost + ", you make " + myprofit + " profit.").

Step III - Create another method in your same class:

. profitOnManySales

Input parameters:
	Double	Price
	Double	Cost
	Int	Quantity sold
Description of processing: The profit is the price minus the cost. Multiply that times the quantity sold for the total profit.
Return:
	Double	Profit

Now test this method:

When you are done, run just the profitOnManySales method in BlueJ passing it a price of 100.02 and cost of 10.01 and quantity of 2 and see 180.02 returned.
Try again with a price of 30 and a cost of 100 and quantity of 3 and see -210 returned.
(If you do not get the right answer, try debugging with the stop sign in the margin of the BlueJ code)

Step IV: Change your main method to print a price on many sales

Code the following:
- After you tell the user the profit on one sale in your main method, do the following:
- Create 2 new variables: int myquantity and set it to 3 AND double profitForQuantity and set it to 0
- Calculate the profit they make when that quantity is sold. (For this exercise, you must use your profitOnManySales method to do that. )
  
  call the profitOnManySales method sending the price and cost and quantity. Be sure to save the answer into a variable
- Tell the user : "By selling " + myquantity + " items, you made " + profitForQuantity + " total profit on this sale."

Test your methd and then change the quantity to 5 and test it again.

Step V: Change your main method to ask for the quantity:

After you tell the user the profit on one sale, ask them "How many did you sell in week 1?" and take in the answer.

Remember to first put "import java.util.Scanner;" above the public class line

put Scanner screenman = new Scanner(System.in); in the first line of your main method to create a Scanner guy named screenman.

call the System.out.println method to print the question "How many did you sell in week 1?"

ask screenman to use its nextInt method to give you the quantity the user just typed and remember to save the answer into your myquantity variable.

Step VI: Change your main method to ask for 5 quantities, one for each week