I do not understand the part of getting the number of mines of neigboring cells

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if(!gameField[y][x].isMine){//if a cell has no mine for(GameObject cell : getNeighbors(gameField[y][x]))//I do not understand this part if(cell.isMine) cell.countMineNeighbors++;//if a cell has a mine //return the number of mines adjacent to this cell? I do not understand how this works } I am buiding this game for the second time and I still do not understand how this part works. I just copied the code from someone else.... Can someone please enlighten me?

At this stage, we'll deal with the logic to reveal cells. Let's create a corresponding method and a variable that will store the cell state (revealed or hidden).

When revealing a cell, the method will:

- draw a mine in the cell if it contains a mine;
- display the number of mined neighbors if the cell does not contain a mine;
- mark the cell as revealed in the model;
- change the cell color.

For convenience, we suggest adding the mine symbol to a separate constant. When the a cell be revealed? Correct! When you click on it with the left mouse button. To handle this click event, the engine has a special method: onMouseLeftClick(int, int).

Let's override it in our class. It will call the method that reveals a cell.

And, of course, run the program and enjoy the results of your work.

Requirements:

The MinesweeperGame class must have a private static final String MINE field that is initialized when it is declared. For example, you can use the UTF-16 symbol for a bomb: "\uD83D\uDCA3".
The MinesweeperGame class must have a private void openTile(int x, int y) method.
The openTile(int, int) method must draw MINE if the gameObject at the passed coordinates is a mine. Use the setCellValue(int, int, String) method.
The openTile(int, int) method must draw the number of adjacent mines if the gameObject at the passed coordinates is not a mine. Use the setCellNumber(int, int, int) method.
The GameObject class must have a public boolean isOpen field.
The openTile(int, int) method should set the isOpen field on the gameField element equal to true and use the setCellColor(int, int, Color) method to draw the cell background. For example, using Color.GREEN.
The MinesweeperGame class must override the Game parent class's onMouseLeftClick(int, int) method.
The onMouseLeftClick(int, int) method must call the openTile(int, int) method.

package com.codegym.games.minesweeper; //import com.codegym.engine.cell.*; public class GameObject { public int x; public int y; public boolean isMine; public int countMineNeighbors; public GameObject ( int x, int y, boolean isMine){ this.x = x; this.y = y; this.isMine = isMine; } }

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daydreaming

Level 22 , Qingdao, China

28 February 2020, 04:00

Yes i think yours partically right. the method [getNetghbors] returns all the neighbors the cell has, then the for-each loop examine the each cell, if the cell is mine , countMineNeighbors++ . after [for(GameObject cell : getNeighbors(gameField[y][x]))] this for-each loop, the neighbors of the cells are examined, i.e. it counts the mines.

Liliane Top

Level 17 , Amsterdam, Netherlands

28 February 2020, 14:19

All of a sudden it clicks! I'm rereading your text and I see now what is actually happening here. You made my day!!

Pawel

Level 22 , Austin, TX, USA

27 February 2020, 19:18

This loop is called for-each, check this link how it works :) https://www.geeksforgeeks.org/for-each-loop-in-java/

Liliane Top

Level 17 , Amsterdam, Netherlands

28 February 2020, 14:09

I checked your link but I still not fully understand how it works in this context....

Stefano Re

Level 5 , Catania, Italy

16 March 2020, 17:58

useful

A foreach cycle act on all the elements of a collection.
Line 62: for(GameObject cell : getNeighbors(gameField[y][x])) you have to consider that getNeighbors(gamefield[y][x]) returns a List of GameObjects (as you can see by the declaration of the getNeighbors method: private List<GameObject> getNeighbors(GameObject gameObject)
The for each is
for(GameObject cell : getNeighbors(gameField[y][x])) It means that on the first pass, you declare a new GameObject variable called cell and you set it equal to the first element of the collection
(it's equivalent to GameObject cell = listElementAtIndex(0);) and you use the variable cell inside the cycle. In the second pass, you still use the variable cell but this time it will be equals to the second element of the collection, like GameObject cell = listElementAtIndex(1); and so on, until it reach the end of the collection. I hope this help you

Liliane Top

Level 17 , Amsterdam, Netherlands

17 March 2020, 12:05

Hi Stefano, Thanks for taking the time to explain. I learn the most from fellow learners! I sort of understand how the for each loop works but there are a couple things I'm not sure about: 1) why do we loop over the cell by gameField [y][x] and not just gameField [x][y]. Why are the x and y exchanged? 2) listElementAtIndex(0) refers to a cell ? with which coordinates as we 're working with an 2D array and not just a straight forward array.

Liliane Top

Level 17 , Amsterdam, Netherlands

17 March 2020, 12:19

As I understand the following correctly: for(GameObject cell : getNeighbors(gameField[y][x])). 1) I understand now that this is a for each loop(thanks for explaining so well!) 2) but we check only those cells that are returned by the method we invoke with getNeighbors() method. hence the surrounding cells of this particular cell 3) the parameter is than a given cell with coordinates gameField[y][x] 4) if any of the surrounding cells has a mine than this will be added to countMineNeighbours 5) the total amount is then added to that particular cell Is the above correct? If so I am still not sure about my first 2 questions in regards to the [y][x] and the listElementAtIndex(0).