与另一个数组中的元素相比，从数组中删除重复的元素

Question

I have the SuperClass Tile extended in many SubClassess such as GroundTile , WallTile , TrapTile etc..
In another Class, lets call it Main , i can use a function that retrieves me all instances of those classes as an array.

Main(){  
  void MyFunctionThatDoesThings(){
    GroundTile[] grounds = FindObjectsOfType<GroundTile>();
    WallTile[] walls = FindObjectsOfType<WallTile>();
    // ... *same code but for other Classes* ...
    Tile[] tiles = FindObjectsOfType<Tile>();
    // ... etc
  }
}

What I need to do is to filter from tiles array the elements that are not already present in the other arrays. Is there a way (or a Linq method) to do this other than Looping through the tiles array, checking if the current element is equal to any element in the other arrays, and if not keep it otherwise delete it?

Answer 1

Tile[] tiles = FindObjectsOfType<Tile>().Except(
    Enumerable.Empty<Tile>()
        .Concat( grounds )
        ...
        .Concat( walls ) ).ToArray();

Answer 2

If you're already storing each array in it's own variable as you show above, then you can filter out the other arrays using the Except() extension method (which you get from using System.Linq; ).

Then you can just do something like:

GroundTile[] grounds = FindObjectsOfType<GroundTile>();
WallTile[] walls = FindObjectsOfType<WallTile>();
TrapTile[] traps = FindObjectsOfType<TrapTile>();

Tile[] tiles = FindObjectsOfType<Tile>()
    .Except(traps)
    .Except(walls)
    .Except(grounds)
    .ToArray();

Answer 3

This might do as an example if I understood correctly:

            List<int> l = new List<int> { 1, 2, 4 };
            List<int> s = new List<int> { 1, 2, 3 };
            var result = s.Where(x => l.Contains(x));

Answer 4

One way to do it is by using LINQ. Assuming you have an ID to identify a particular object.

GroundTile[] grounds = FindObjectsOfType<GroundTile>();
WallTile[] walls = FindObjectsOfType<WallTile>();
// ... *same code but for other Classes* ...
Tile[] tiles = FindObjectsOfType<Tile>();

var existingTiles = grounds.Union(walls);

tiles = tiles.Where(t => existingTiles.All(e => e.ID != t.ID)).ToArray();