Snake[18/20] - Don't know the problem

Question about the task

Under discussion

I wrote exactly what it tells me to do, and if you run, the snake doesn't move properly. If I write the right thing, and the game works fine, it doesn't checks either.

Let's fix our snake control. The direction field can only be changed to currently valid values: LEFT, RIGHT, UP, and DOWN.

Requirements:

The Snake class's setDirection(Direction) method must not do anything if the value of the direction field is LEFT, and the snake segments with indices 0 and 1 in the snakeParts list have the same x coordinate.
The Snake class's setDirection(Direction) method must not do anything if the value of the direction field is RIGHT, and the snake segments with indices 0 and 1 in the snakeParts list have the same x coordinate.
The Snake class's setDirection(Direction) method must not do anything if the value of the direction field is UP, and the snake segments with indices 0 and 1 in the snakeParts list have the same y coordinate.
The Snake class's setDirection(Direction) method must not do anything if the value of the direction field is DOWN, and the snake segments with indices 0 and 1 in the snakeParts list have the same y coordinate.

package com.codegym.games.snake; import com.codegym.engine.cell.*; public class Apple extends GameObject { public boolean isAlive = true; private static final String APPLE_SIGN = "💸"; //💰 public Apple(int x, int y) { super(x, y); } public void draw(Game game){ game.setCellValueEx(x,y, Color.NONE,APPLE_SIGN,Color.GREEN,75); } }

Comments (9)

Popular
New
Old

You must be signed in to leave a comment

Jeremy Hornick

Level 16 , Canada

14 August 2019, 14:25

I completely agree Ewerton. The requirements make no sense to me and the code doesn't work. If you switch the x and y's in the requirements it works but fails testing.

public void setDirection(Direction direction)
    {
        if(direction==Direction.LEFT || direction==Direction.RIGHT) {
            if(snakeParts.get(0).x == snakeParts.get(1).x)
                return;
        }

        if(direction==Direction.UP || direction==Direction.DOWN) {
            if(snakeParts.get(0).y == snakeParts.get(1).y)
                return;
        }

        this.direction=direction;

    }

Jeremy Hornick

Level 16 , Canada

16 September 2019, 15:49

I am such an idiot. I should have read zhaoyang's answer a little closer a month ago. The key is to look at the class member (field) and not the parameter passed to the function.

Pablo Souza

Level 22 , Brisbane, Australia

4 May 2020, 02:51

One question though. In your if statement, both directions (the current and the passed) have the same name. How do you know which one is the current direction and which one is the passed direction?

zhaoyang

Level 25 , Los Angeles, United States

14 July 2019, 17:24

hi, I also get stuck on this problem for a while. And finally i got it. first, you should not delete the previous code that is when direction is opposite, it will not change. This task is ask you to add more restriction on it. second, notice that in the requirement it says the value of the direction field, not the direction parameter. So, correct me if I'm wrong, the bug is if when the snake's current direction is left but the first and second segments has same x coordinate, the setDirection() method cannot change the snake's current value. And this situation is happened only if the keyboard input is very quick and the snake's direction has be changed but it has not changed it's body since there has delay in every turn. So, imagine that if you don't fix this bug, if the snake go right, and user quick input Key.up and Key.left, the snake will change his body directly to left, and dead.

Liliane Top

Level 17 , Amsterdam, Netherlands

29 February 2020, 18:20

what is the difference in this context between: second, notice that in the requirement it says the value of the direction field, not the direction parameter. I'm very confused....

Pablo Souza

Level 22 , Brisbane, Australia

4 May 2020, 02:41

I got it now... Try this... If your snake is moving down and you press left and then up very quick (before it changes), it dies. So you have to increase requirements.

Liliane Top

Level 17 , Amsterdam, Netherlands

4 May 2020, 07:14

I finally figured it out why. You're right the snake dies if you change directions too fast. I now understand how it works and how to adjust the code. My snake game is working properly.

Norbert Backend Developer

28 July 2020, 15:42

Could you tell me how to change the code to make it work, because I don't know how to do it anymore

Level 41

10 July 2019, 08:30

Snake class should not be inherited from GameObject class