Why are these objects always equal using ==? (Solved)

News & General Discussion
1

I recently followed a pathfinding tutorial and ran into a strange problem that only I seem to be having. There is a class called PathNode which stores x and y values and I create a grid of these pathnodes for the pathfininding. The A* pathfinding algorithm is unable to perform its logic since no matter what I do, unity always sees all PathNodes as being equal to all other PathNodes. If I create a simple test script to create some pathnodes and check their equallity with ==, Unity always says they are equal. The most confusing part of this is I cant find a solution to this because it seems like I am the only one dealing with this issue. What’s happening here?

public class PathNode : MonoBehaviour
{
    public int x;
    public int y;

public PathNode(int x, int y)
    {
        this.x = x;
        this.y = y;
    }

private void Start()
    {
        PathNode pathnode1 = new PathNode(0, 0);
        PathNode pathnode2 = new PathNode(1, 1);

        if(pathnode1 == pathnode2)
        {
            Debug.Log("pathnodes are equal");
        }
    }
2

Unable to replicate, which version of unity is it?

3

2020.1.3

4

I suggest to check hashCode of these two objects. It appears, they will be equal.

5

Just guessing but you do not instance the monobehavioirs correctly and there for the equals overload does not work as it should

1 Like
6

I think you might have just hit the nail on the head. I don’t think these need to inherit monobehavioir. I feel like a dope! Thank you.

1 Like
7

I think that you should either implement your own Equal method or compare x and y values directly instead of comparing two class instances.
You also could implement the IEquatable interface on your class.

https://stackoverflow.com/questions/8400028/comparing-two-instances-of-a-class

Since pathnode1 and pathnode2 are two different instance of the PathNode class, pathnode1 will never be equal to pathnode2 even if x and y values are equals.

You could add a method like static bool Equal(PathNode first, PathNode second) and adding the x and y comparaison inside.

8

Thanks for the info. It turns out it was actually the monobehavior as MDADigital pointed out but I will read up on the source you provided since I am now curious about the subject.