For foreign language learners, it’s hard to remember new words, which is exactly what flashcards are for. Typically, flashcards show a hint (a task or a picture) on one side and the right answer on the other. Flashcards can be used to remember any sort of data, so if you want to create something useful and enhance your programming skills, this project is just right.
You will learn to work with files and call them from the command-line.
Java Developer
You may already know that a flashcard is a piece of paper that contains a term on one side and a related text you want to remember on another one. Flashcards are often used to learn a foreign language, so let's say this text is just a definition of the term.
We offer you to create an application that emulates a set of flashcards on a screen. While developing this application, you not only learn programming, but also save paper!
As a start, implement a program that outputs a single term and its definition. You can print a term and a definition you like in this stage. How to submit?
This stage is auto-graded. The grader will check that:
- you output 4 lines,
- the first line is
Card:, - the third line is
Definition:.
We cannot play Flashcards with only one card, right? Let's make our program dynamic! Implement a custom card creation mechanism. Read a term and a definition from the console and create a card.
After that, a user inputs a line as an answer (a definition of the card). Compare the user's answer to the correct definition and print the verdict. How to submit?
This stage is auto-graded. The grader will input 3 lines (term, definition, answer) and check that your output contains a word:
- wrong if the answer isn't equal to the definition,
- right if the answer is equal to the definition.
Again, here are some examples to clarify the stage.
Your program is able to play using one card. Let's make our game serious and implement a set of cards now!
Let the user decide how many cards they would like to keep. First, ask the player to enter the desired number of cards. Then, ask to input the term and the definition of every card. If the initial number was 100, then... well, what a pity!
In the end, when all of the cards are defined and saved, your program is finally ready to play! Question the player about all the new words they have entered. The program should give the term and ask for a definition. Let the game begin!
This stage is auto-graded. The grader will behave as in example, so you can change an internal logic of your code, but the output should be similar. Here are some important notes:
- When you ask for a definition of a card, you should write the term of the card in quotes. Example:
Print the definition of "black":. - If the answer is correct, you should print
Correct answer.. And if the answer is wrong, you should printWrong answer. The correct one is "black"., where"black"is the correct definition.
Imagine a situation: the answer is wrong for the given term, but it is correct for another term. Let's consider situations like this.
You can use maps. Ask all card's definitions in the order of addition. If the definition is wrong for the current term but it is correct for another, output the original term.
When the user tries to add a duplicated term or definition, forbid it and ask again until the user inputs a unique one. For now, you are able to implement this without a try catch construction. Use the rule: if you can avoid exception-based logic, avoid it!
Improve the application's interactivity. Ask the user for action and make it.
Support these actions:
- add a card: add,
- remove a card: remove,
- load cards from file: import,
- save cards to file: export,
- ask for a definition of some random cards: ask,
- exit the program: exit.
When entering the word export, the program should request a file name and write all currently available cards into this file. When entering the word import, the program should request a file name and read all the cards written to this file.
You can use any format to save cards to the file. Tests do not check the content of the file, but they do check that all saved cards are loaded correctly.
In this stage, if you try to add a card with an existing term or an existing definition, the application must just reject it by printing an error message (see example 1).
When you load cards from a file, you shouldn't erase the cards that aren't in the file. If the imported card already exists, it should update the old one (look at cards Japan and Moscow in the example 2). It is guaranteed, that there won't be any conflicts with definitions in the tests.
Add some statistics features. We suggest you implement the following:
- Action log saves the application log to the given file. Save all lines that have been input in or output to the console to the file. You can use a list to store the lines.
- Action hardest card prints the term of the card that has the most mistakes. You can store the mistake count in a map. If there are no cards with mistakes, you should print There are no cards with errors.. And for multiple hardest cards, you should list them all, like in the example below.
- Action reset stats erases the mistake counts for all cards.
Also you should update serialization/deserialization to store sets of three items (term, definition, mistakes) instead of pairs (term, definition).
Users often use files to save their progress and restore it the next time they run the program. It's tedious to print the actions manually. Sometimes you can just forget to do it! So let's add run arguments that define which file to read at the start and which file to save at the exit.
To read an initial cards set from an external file, you should pass the argument -import and follow it with the file name. If the argument is present, the first line of your program output should be 10 cards have been loaded. (hereinafter, replace 10 with the number of cards). If such argument is not set, the set of cards should be initially empty.
If the -export argument is set and it is followed by the file name, you should write all the cards that are in the program memory into this file after the user has entered exit, and the last line of your program should be 10 cards have been saved..
java Flashcards -import derivatives.txt
java Flashcards -export animals.txt
java Flashcards -import words13june.txt -export words14june.txt
java Flashcards -export vocab.txt -import vocab.txt