How to Randomly disable box collider in unity - unity3d

Question

i have two simple 3d cube objects a,b. so my task is to randomly disable box collider one of the object every time game start.
my initial thought is randomly generate Boolean and if it is false then disable the box collider.

Answer 1

You can add you cube's to array and use Random.Range(0, yourArray.Length) to get index of the cube which should be deactivated. In your case it will be some overhead but this solution will be work for different cube`s count in the future.
In code it will looks like:
// You can serialize this array and add cubes from Inspector in Editor
// or add script with this code to the parent gameobject
// and use GetComponentsInChildren<BoxCollider>() to get all colliders
var cubes = new BoxCollider[2] {firstCube, secondCube};
var cubeToDeactivationIndex = Random.Range(0, cubes.Length);
cubes[cubeToDeactivationIndex].enabled = false;
About your second question. If I understand correctly, implementation will be next:
using System;
using UnityEngine;
using UnityEngine.Assertions;
using Random = UnityEngine.Random;
// Interface need to provide limited API
// without open references to gameobject and transform of the object
public interface ICollidable
{
event Action<ICollidable> OnCollided;
int HierarchyIndex { get; }
void DisableCollider();
}
// This component you should add to the object which will collide with player
public class CollidableObject : MonoBehaviour, ICollidable
{
[SerializeField]
private Collider _objectCollider;
public event Action<ICollidable> OnCollided;
public int HierarchyIndex => transform.GetSiblingIndex();
private void Start()
{
Assert.IsNotNull(_objectCollider);
}
//Here you can use your own logic how to detect collision
//I written it as example
private void OnCollisionEnter(Collision collision)
{
if (collision.transform.CompareTag("Player")) {
OnCollided?.Invoke(this);
}
}
public void DisableCollider()
{
_objectCollider.enabled = false;
}
}
// This component should be on the parent gameobject for your `
// collidable objects. As alternative you can serialize array
// and add all collidable objects from the Inspector but in that
// case signature of the array should be CollidableObject[]
// because Unity can`t serialize interfaces
public class RamdomizedActivitySwitcher : MonoBehaviour
{
private ICollidable[] _collidableObjects;
private void Awake()
{
_collidableObjects = GetComponentsInChildren<ICollidable>(true);
foreach (var collidable in _collidableObjects)
{
collidable.OnCollided += DisableObjectWhenMatch;
}
}
private void DisableObjectWhenMatch(ICollidable collidedObject)
{
var randomIndex = Random.Range(0, _collidableObjects.Length);
if (randomIndex == collidedObject.HierarchyIndex) {
collidedObject.DisableCollider();
}
}
}
}