Level 15

Delhi

17.01.2020
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12comments

Last two requirements not meeting

Question about the task

Under discussion

An object on the playing field can have one of two states: it can be alive (isAlive=true) or dead (isAlive=false).
For example, if the snake hits the edge of the playing field, it dies. The same thing happens to an apple when it is eaten by the snake. To store object state, create a boolean isAlive variable in the Apple and Snake classes. Modify the logic for drawing a snake so that dead snakes are red.

The snake can move in one of four directions. To indicate these directions, create a Direction enum with UP, RIGHT, DOWN, and LEFT fields.

And in the Snake class, create a direction field, which will store the current direction of movement. Let the snake initially move to the left. The snake's direction will be changed by the setDirection(Direction) method. Create it.

Requirements:

The Apple class must have a public boolean isAlive field that is initialized to true.
The Snake class must have a public boolean isAlive field that is initialized to true.
In the Snake class's draw(Game) method, replace all calls to the setCellValue(int, int, String) method with calls to the setCellValueEx(int, int, Color, String, Color, int) method using arguments (x, y, Color.NONE, HEAD_SIGN (or BODY_SIGN), <color of snake>, 75). If the snake is dead, its color must be Color.RED. Otherwise, any other color, for example, Color.BLACK.
There must be a public Direction enum with the following values: UP, RIGHT, DOWN, LEFT.
The Snake class must have a private Direction direction field that is initialized to Direction.LEFT when it is declared.
The Snake class must have a public setter for the direction field: setDirection(Direction), which assigns the passed value to the field.

package com.codegym.games.snake; import com.codegym.engine.cell.*; public class SnakeGame extends Game { public static final int WIDTH = 15; public static final int HEIGHT = 15; private Snake snake; public void initialize() { setScreenSize(WIDTH,HEIGHT); createGame(); } private void createGame() { snake = new Snake(WIDTH/2,HEIGHT/2); drawScene(); //Apple apple = new Apple(7,7); //apple.draw(this); } private void drawScene() { for(int i=0;i<WIDTH;i+=1) { for(int j=0;j<HEIGHT;j+=1) { setCellColor(i,j,Color.DARKSEAGREEN); } } snake.draw(this); } }

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Antali András

Level 17 , Budapest, Hungary

17 January 2020, 17:56

Hello, It is maybe just a lack of a semicolon in the Direction class. You have to put a semicolon after the list: public enum Direction { UP, RIGHT, DOWN, LEFT; } I hope this will help, the Snake class seems fine.

Guadalupe Gagnon

Level 37 , Tampa, United States

17 January 2020, 19:00

A semi-colon is not needed here

Antali András

Level 17 , Budapest, Hungary

17 January 2020, 20:08

Yes, my mistake. I always use it - it does not seem to be a fault. All right.

Guadalupe Gagnon

Level 37 , Tampa, United States

17 January 2020, 15:58

Is the Snake class supposed to extend GameObject?

Antali András

Level 17 , Budapest, Hungary

17 January 2020, 20:36

No, the Snake does not have to inherit any other Class. And I found a further problem with the draw method. It only draws 3 elements in a special location. But later, if the snake turns, and grows, this method will be unable to draw correctly.

Guadalupe Gagnon

Level 37 , Tampa, United States

17 January 2020, 21:14

The draw method may change in a later part to the big task. These big tasks are really hard to help people on because I don't know if the differences in code are because they are doing it wrong, or the task hasn't reached the part where it is "final".

Antali András

Level 17 , Budapest, Hungary

17 January 2020, 21:43

I have already finished this game, but I do not remember if it would have been a future task at this point. (Was my English correct? I seldom use English language outside of CodeGym...) Just in case, I think it would be better to correct this drawing part now. It could be harder to search for this bug later. Nikes, if you want, I will help you in this. But (back to your original issue) I cannot find any other problems but the failed inheritence we already talked about.

Guadalupe Gagnon

Level 37 , Tampa, United States

17 January 2020, 23:27

Your English is good, I wouldnt know that you never used it if you hadn't mentioned it.

Antali András

Level 17 , Budapest, Hungary

18 January 2020, 19:45

Good to read this from a native speaker, thank you.

Nikesh

Level 15 , Delhi, India

20 January 2020, 09:53

Hi Antali, As snake is also a game object like apple it must inherit GameObject. If I don't inherit it then class will never know the value of x and y in constructor class. But thanks for reply ppl.

Antali András

Level 17 , Budapest, Hungary

20 January 2020, 11:52

It is not an IS-A, but a HAS-A relationship. Your 7th row is right:


private List<GameObject> snakeParts = new ArrayList<>();

Not the whole snake is a GameObject, but its parts, because a GameObject is only one (x, y) pair. The whole snake cannot be described with an (x, y) coordinate, just the parts of the snake. (Believe me, my game is finished and works. :) ) So I recommend you to delete the ("extends GameObject" part from the class head. And also delete the super(x, y); row from the Snake constructor.

Guadalupe Gagnon

Level 37 , Tampa, United States

20 January 2020, 14:15

I agree with Antali. I didn't find a part in this big task for this game that asks you to extend GameObject. The x and y variables in the constructor are specifically for the snakeParts list. The specific task that asks you to create the Snake class is part 5 and continues in part 6: https://codegym.cc/tasks/com.codegym.games.snake.part05 https://codegym.cc/tasks/com.codegym.games.snake.part06