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TheDoctor, Professional w/Adv. Degree
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Experience:  M.S. in Internet Information Systems
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Question for TheDoctor. The file with my Java problem is located at I need the solution by Monday 19th June. Thanks.

Hello again! Thank you for requesting me.

I will contact you once this is complete.

Hello again!

You can download the completed project here:


Within the zip file, you will find the java file, the text files, and the Microsoft Word document with testing information and conclusions.

To compile the project, you must run javac

Once it is compiled, it must be run with the file arguments. For instance, you would run the cars one like this:

java Calc car.txt carRules.txt

And you would run the stocks one like this:

java Calc stock.txt stockRules.txt

I commented the entire project, and it meets all of the requirements.

Let me know if you have any questions. I'm here to help.

Please remember to rate my answer. Thank you so much and have a wonderful day!


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TheDoctor and 3 other Homework Specialists are ready to help you
Customer: replied 4 years ago.

Could you please explain the appended part of the code below? Why do you use rules[1] inside switch? How does this work?

//Call the rule, replace the value in the spread sheet
switch(rules[1]) {
case "mean":
sl[Integer.parseInt(rowAndColumn[1]) - 1] = mean(rules[2], rules[3]);
case "max":
sl[Integer.parseInt(rowAndColumn[1]) - 1] = max(rules[2], rules[3]);
case "min":
sl[Integer.parseInt(rowAndColumn[1]) - 1] = min(rules[2], rules[3]);
case "sum":
sl[Integer.parseInt(rowAndColumn[1]) - 1] = sum(rules[2], rules[3]);

Hello again, Michael.

First, let me point out that this particular bit of code required JDK7 or higher. (JDK7 is the current).

This is a standard switch case. A switch is a basic condition structure found in almost all modern programming languages. It is a cleaner alternative to using if...else if...else if...else if...else if

Rules is an array that holds a single line from the rules file.

rules[0] is equal to the cell address
rules[1] is equal to the function that is to be performed
rules[2] is the from cell address
rules[3] is the to cell address

So, what we are saying with this is, if the function to be performed (rules[1]) is equal to mean... else if it is equal to max... else if it is equal to min... else if it is equal to sum

Strings in a switch case have been a standard part of programming for quite a long time. You will find switch cases in C++, C#, PHP, JavaScript, ActionScript, etc.

It has also been a standard part of Java for a very long time, and is usually covered in the chapter about control structures in an Java text books (this is usually in the first few chapters). However, Java was the only modern language that supported ONLY integers in switch cases.

Developers complained for well over a decade about this. After all, the switch case is considered one of the most basic and important control structures in modern programming. And Java only partially supported it.

As of JDK7, Java now fully supports the switch case (using String cases).

Most instructors would expect you to use a switch instead of a large number if if/else if statements. In addition, I have actually rejected developer code in the real world because of that. Many organization conduct code reviews wherein a senior developer or lead engineer helps review the code of more junior team members, or the entire team reviews code together. As a lead engineer, I have had to reject code due to the use of excessive if/else if statements. It is simply sloppy programming. That is why the Switch Case control structure exists in almost every modern language.

Let me know if you have any other questions.

Have a wonderful day.

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