The description says the code will accept a number between 5 and 10 but the code will accept a number between 4 and 10.

viestit is left untranslated to English.

Wrong:

if (!viestit.contains(sms)) {
    messages.add(sms);
}

Right:

if (!messages.contains(sms)) {
    messages.add(sms);
}

For the quiz "Executing conditional statements" the question and code are duplicated and mentioned twice. Once left-aligned, and the other center-aligned.

quiz id="cf7bfa61-dc45-56f2-8913-fa8671dbfc4d"

although lambda expressions do have their place, they have the same problem as anon inner classes: you cannot access them easily, so testing, also from the students perspective, is hard. To improve testability use method references instead,
like this::digitHandler, which will allow the (pack private ) void digitHandler(event) to be tested separately. That would allow testing the business of the handler.

The example code mis represents type erasure and makes it look like the Locker has been specialized by the compiler. That is not how Java works. All occurrences of type are replace by Object, and at the call site a cast to the proper type is applied.
Locker knows nothing of its content.

public class Locker {
    private Object element;
    public void setValue(Object element) {
        this.element = element;
    }
    public Object getValue() {
        return element;
    }
}

At the call site the compiler knows that the cast is allowed:

  String r = (String) Locker.getValue();

Generic information is primarily used by the compiler to proof the code. Once it is satisfied it removes (erases) the generic information. The drawback is that that information is hard to retrieve at runtime. The benefit is that you do NOT have to specialize classes, and fore-most that the compiler can do its job of ensuring type-safeness. Also type-erasure allows backward compatibility, you can mix old (compiled code) and new.

Part07_08.BigYear finish word for "Quit" now in English, which I updated it to be English when the mainProgram is displayed for the demonstration.

In Line 20, the word 'luvut' has been given instead of the word 'numbers'. This results in the local run tests to not compile and results in an error.

Existing line : System.out.println(luvut.get(0));
Corrected line : System.out.println(numbers.get(0));

Hello, I had to create a ".../src/main/java/" directory in the part04-Part04_10.Song exercise to complete the exercise.

In the part 6 of the course, one of the example use case in exercise Santa's Workshop in sub-part 1 (Objects on a list and a list as part of an object) contains a code error. Because the class name is Package, in the example code the object is instantiated with the following code:
Package package = new Package();.
This code does not compile because "package" is a Java keyword and cannot be used as an identifier. I suggest renaming the object something error-less. Below, I present the screenshot where the issue happens at.

In the first quiz of the part 9-1 it says the answer is 8, but when i run the code in my IDE i get 2, i think this is probably an error?

the toString() method attempts to return "this.nimi" which I assume is meant to return "this.name" ?

The prompt in the exercise states: "If multiple names are equally longest, you can print any of them."

In test3(), the longest names are "martin" and "mickey". However, the test only accepts "martin" as the correct answer instead of both "martin" and "mickey" since both are 6 characters long.

It was not confusing for me to figure out and change my solution to work with the 'correct' name, but I could see how it could be potentially confusing and frustrating for people who might not see it immediately.

The output is expected to print the sound using a public void sound method but it is not mentioned in instructions to create a method

In part 6, sub-part 1, part 1 of the exercise "Height Order" contains a typo that causes the code not to compile. I attach a screenshot of the erroneous part below. (The sysout statement in red rectangle) The issue is that the class name (Person) , rather than the variable name (person), is used inside the enhanced for loop.

In my mind, it supposed to be "5 ", so I tried it, but that failed. So I tried just "5", and that failed too.

Just to make sure I ran the code it did print "5 "

Trying to answer the "Overloading a constructor" quiz. After clicking submit the submit button greys out. Whilst trying to checking scores I get the error "Fetching progress data failed with the following error: Error: Request failed with status code 500"

In the file Apartment.java at section 5_11, the instance variable princePerSquare should be written as pricePerSquare.

TMCBeans (the snap package) does not launch by clicking its icon in the start menu (at least on Solus Linux 4.1 running the Plasma 5.18.4 desktop). The solution is to launch it from the terminal, when doing so it launches like normal, with the following message:

WARNING:` An illegal reflective access operation has occurred
WARNING: Illegal reflective access by org.netbeans.ProxyURLStreamHandlerFactory (file:/snap/tmcbeans/5/tmcbeans/platform/lib/boot.jar) to field java.net.URL.handler
WARNING: Please consider reporting this to the maintainers of org.netbeans.ProxyURLStreamHandlerFactory
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release

https://github.com/rage/java-programming/blob/master/data/slideshows/test-driven-development.pdf has some errors in the code on the right.

class diagram is:
[Show]<-*[Ticket]
[Show|- movie: String;- time: String]
[Ticket|- seat: int;- code: int]
there should be:
[Show]<show-[Ticket]
[Show|- movie: String;- time: String]
[Ticket|- seat: int;- code: int]

Part "When Should Hash maps Be Used?" contains four paragraphs written in Finnish.

The exercise text talks about a completed command and a remove command, which appear to do the same, but only the remove command is wanted by the tests and used in the reference solution.

The description states, "Create a class called ToDoList. It should have a constructor without parameters and the following methods:"

When you run the code it checks for a class called TodoList instead of ToDoList.

TMC return IOException: No space left on device on the tests:
ReadingFilesPerLineTest methodReturnsLines
ReadingFilesPerLineTest methodReturnsLines2

Locally ReadingFilesPerLineTest.java is all green when ran.

part04-Part04_11.Film
part04-Part04_12.Gauge
part04-Part04_14.Multiplier
All need …\src\main\java directories created.
Thanks.

The points are not being displayed and only the "loading interface" animation is playing.

There is also a message saying "Error loading exercise details" underneath the sample output.

Seen here: https://java-programming.mooc.fi/part-1/4-variables

Above the quiz that asks you to do a questionnaire, the questionnaire is missing and replaced with the following error:

Cannot load a part due to an error:
Error: Network Error

I primarily use Firefox (version 84.0.1) on Windows with uBlock Origin. I turned off uBlock Origin for a moment to see if it was that, but the same error persisted. The same is true in Chrome (version 87), both with uBlock Origin on and off.

When downloading the tasks for week 6, task 6.3 and 6.4 still appear under a finish name.
This can be fixed in the pom file.
part 6.3

 <artifactId>Part06_03.MessagingService</artifactId>
    <name>Part06_03.MessagingService</name>

part 6.4

 <artifactId>Part06_04.PrintingACollection</artifactId>
    <name>Part06_04.PrintingACollection</name>

I thought that the answer was 2, but submitted it and it was wrong. Ran the code in my IDE and got 2 as the answer also, however the quiz says the correct answer is 8.

The first example in "Hash map as an Instance Variable" contains wrong comments.

Should be:

Tested with the following code:

Students and teachers alike like to play with the newest things.
Java 8 is boring, Java 11 is already ancient and Java 15 (at the time of writing) is the newest release.
However, the profile selection in the pom files allows either java 8 or java 11.
By changing the activation value from 11 to e.g [11,16) (Open range start at 11 and accept everything below 16) would
allow the us of newer java versions than 11. See snippet below.

<id>java11</id>
      <activation>
           <jdk>[11,16)</jdk>
      </activation>

https://java-programming.mooc.fi/part-5/4-objects-and-references#programming-exercise-nullpointerexception

Main program given as
`public static void main(String[] args) {
// example main program for the first section of the exercise

HealthStation childrensHospital = new HealthInstitution();

Person ethan = new Person("Ethan", 1, 110, 7);
Person peter = new Person("Peter", 33, 176, 85);

System.out.println(ethan.getName() + " weight: " + childrensHospital.weigh(ethan) + " kilos");
System.out.println(peter.getName() + " weight: " + childrensHospital.weigh(peter) + " kilos");

}`

In the above,
HealthStation childrensHospital = new HealthInstitution();
should instead be
HealthStation childrensHospital = new HealthStation();

The import command for Scanner utility is missing in the main java exercise template.

Line 2 : import java.util.Scanner;

public class ReadingList implements Readable {
    private ArrayList<Readable> readables;

    public ReadingList() {
        this.readables = new ArrayList<>();
    }

    public void add(Readable readable) {
        this.readables.add(readable);
    }

    public int luettavia() {
        return this.readables.size();
    }

The "luettavia()" is not translated to English. It should be "toRead()"

This code is before the "Interface In A Box" exercise

My test cases were not passed because of error, which i think is probably because in second example when entered Ada and a Data Scientist , it print "a" two times.
We haven't taught anything advance to deal with this type of issue in course till now.
Can you please look into the matter and help.
Thanks & Regards,
Trapti.

Duplicate text in Quiz Division (quiz id = a1b73ba2-e36e-5db5-99d3-991c502a94ea)

Couldn't find where quizzes are located to try and solve this typo, if anybody can point me in the right direction I can try and fix it myself and open a new pull request.

The quiz "Overloading a constructor" forgot to translate vuotta to years.

Constructor is named Item in description when it should be named Product to correspond to class name.

This exercise's examples till part 2, use integer value as weight parameter on class constructors even though weight values have to be double, as stated in the exercise.

The term "parameter" is used throughout the course to describe an argument passed to a method, function or class.
A parameter is the described inputs where the method, function or class is authored (ie. the actual method definition fx.).
"argument" should instead be used about the values passed on invocation.

I've created this issue as i believe how we communicate about code is vital - specially at the "beginner stage" as "poor" definitions, like this one, leads to blog posts, conversations, documentation etc. down the line with misleading terms.

The code example in the section "Separating application logic and user interface logic" is broken. Partly because some of the method names have not be translated. But also because, for example, there is no Person class which would be needed for this code to actually run... I'm not totally sure what needs to be done so I won't be touching it for now

As far as I can see this is not used anywhere in the exercise. Please confirm.

Hi. First of all, thank you for presenting such a great course.

I think there is a bug in exercise Part12_10.MagicSquare. The sumsAreSame method of the MagicSquare class does not work properly.

In the following code:

    public boolean sumsAreSame() {
        ArrayList<Integer> sums = new ArrayList<>();
        sums.addAll(sumsOfRows());
        sums.addAll(sumsOfColumns());
        sums.addAll(sumsOfDiagonals());

        if (sums.size() < 3) {
            return false;
        }

        for (int i = 1; i < sums.size(); i++) {
            if (sums.get(i - 1) != sums.get(i)) {
                return false;
            }
        }

        return true;
    }

The method's purpose is to check if all elements in sums are of the same value. But since the type of element in sums is Integer which is a reference type, comparing two elements using != will produce true for two Integer objects that contain the same value. IMHO, it seems that the comparison wrongly compares reference of the two objects instead of their values in logic.

A possible fix could be:

for (int i = 1; i < sums.size(); i++) {
    if (!sums.get(i - 1).equals(sums.get(i))) {
        return false;
    }
}

Or:

if (sums.stream().distinct().count() > 1) {
    return false;
}

This bug will further affect isMagicSquare method of MagicSquare class, which makes the last part of this exercise confusing.

In example from material, program is be able to detect index from multiple smallest number
but test case does not cover it and let program that detects only single smallest number passes.

Example program

72
44
8
8
11
9999

Smallest number: 8
Found at index: 2
Found at index: 3  // Pass

User program

72
44
8
8
11
9999

Smallest number: 8
Found at index: 2    // Pass but it should not.

Possibly require the following changes in SportStatisticTest.java (?):

-- io.setSysIn(fileName + "\nspiderman\n");
++ io.setSysIn(fileName + "\nsuperman\n");

-- assertTrue("With the file:\n" + textToWriteToTheFile + "\nWhen searcing for superman the output should have the line \" Wins: 0\".\nthe output was:\n" + io.getSysOut(), lines(io.getSysOut()).stream().filter(l -> l.contains("Wins: 0")).count() == 1);
++ assertTrue("With the file:\n" + textToWriteToTheFile + "\nWhen searcing for superman the output should have the line \" Wins: 1\".\nthe output was:\n" + io.getSysOut(), lines(io.getSysOut()).stream().filter(l -> l.contains("Wins: 1")).count() == 1);

The tests pass after making these changes locally.

Here's the original unit test:

    @Test
    @Points("04-31.2")
    public void winsAndLosses3() {
        String fileName = "file1.txt";
        String textToWriteToTheFile = "bestTeam,superteam,32,34\nbatman,superman,30,31\nbatman,robin,1,0\ncats,dogs,3,0";
        deleteAndCreateNew(fileName, textToWriteToTheFile.split("\n"));
        io.setSysIn(fileName + "\nspiderman\n");
        
        try {
            SportStatistics.main(new String[]{});
        } catch (Exception e) {
            fail("Error when running the program: " + e.getMessage());
        } finally {
            deleteFile(fileName);
        }
       
        assertTrue("With the file:\n" + textToWriteToTheFile + "\nWhen searcing for superman the output should have the line \" Wins: 0\".\nthe output was:\n" + io.getSysOut(), lines(io.getSysOut()).stream().filter(l -> l.contains("Wins: 0")).count() == 1);
        assertTrue("With the file:\n" + textToWriteToTheFile + "\nWhen searcing for superman the output should have the line \" Losses: 0\".\nthe output was:\n" + io.getSysOut(), lines(io.getSysOut()).stream().filter(l -> l.contains("Losses: 0")).count() == 1);
    }

I'm wondering if it should be:

@Test
    @Points("04-31.2")
    public void winsAndLosses3() {
        String fileName = "file1.txt";
        String textToWriteToTheFile = "bestTeam,superteam,32,34\nbatman,superman,30,31\nbatman,robin,1,0\ncats,dogs,3,0";
        deleteAndCreateNew(fileName, textToWriteToTheFile.split("\n"));
        io.setSysIn(fileName + "\nsuperman\n");
        
        try {
            SportStatistics.main(new String[]{});
        } catch (Exception e) {
            fail("Error when running the program: " + e.getMessage());
        } finally {
            deleteFile(fileName);
        }
       
        assertTrue("With the file:\n" + textToWriteToTheFile + "\nWhen searcing for superman the output should have the line \" Wins: 1\".\nthe output was:\n" + io.getSysOut(), lines(io.getSysOut()).stream().filter(l -> l.contains("Wins: 1")).count() == 1);
        assertTrue("With the file:\n" + textToWriteToTheFile + "\nWhen searcing for superman the output should have the line \" Losses: 0\".\nthe output was:\n" + io.getSysOut(), lines(io.getSysOut()).stream().filter(l -> l.contains("Losses: 0")).count() == 1);
    }

The word nimi is left untranslated to English in this quiz. The code will not compile as is.

Wrong:
this.nimi.equals(compared);

Right:
this.name.equals(compared);

There is a typo in the example code of the exercise named "Cargo Hold (Part 4)", which is located in the subpart-1 of the Part 6 of the course. The task instruction requests the student to write a method named "printGoods()" but the example code snippet includes a method named "printItems()". The method name in the instruction should be renamed to "printItems()" because the underlying unit tests check for the existence of a method named "printItems()".

Below is the code where this error happens.

the correct answer should have been 0 but answer is shown 4

There's only one quiz in Part6 under Complex programs section worth 1 point.
But the evaluator is considering it worth 5 points and hence showing only 20% is completed.

In part 4 exercise 15 the following sentence appears in its description where 'in the' is written twice:

Create a class Statistics that has the following functionality (the file for the class is provided in the in the exercise template):