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Java Introduction to Functional Programming Meet Streams flatMap

Posted by Andrey Serebryanskiy
Andrey Serebryanskiy
5,756 Points

Can this piece of code be replaced with something functional?

Hey!

I have a simple Minesweeper game. When I create a field for it, I go through each cell of two-dimensional tile array and put a new Tile there. X and y are important because they are further used to add a tile to a GridPane.

xTiles - is number of tiles horizontally

yTiles - vertically.

The last argument in new tile creation determines if this tile would have a bomb. 

Tile[][] tiles = new Tile[xTiles][yTiles];
for(int y = 0; y<yTiles; y++) {
   for(int x = 0; x<xTiles; x++) {
      tiles[x][y] = new Tile(x, y,Math.random() < 0.15);
   }
}

Can this massive piece of code be replaced with more succinct and understandable stream?

2 Answers

Thomas Nilsen
Thomas Nilsen
14,957 Points

You can probably do something like this:

IntStream.range(0, xTiles)
         .forEach(r -> IntStream.range(0, yTiles)
                                .forEach(c -> array[r][c] = new Tile(r, c)));

or something like this:

Tile[][] array = IntStream.range(0, xTiles)
                .mapToObj(r -> IntStream.range(0, yTiles)
                                        .mapToObj(c -> new Tile(r, c))
                                        .toArray(Tile[]::new))
                .toArray(Tile[][]::new);
Andrey Serebryanskiy
Andrey Serebryanskiy
5,756 Points

Thank you, Thomas, you've provided a very beautiful decision.