Can't increase my score after OnTriggerEnter occurs.

Questions & Answers
1

I am trying to implement a score system and I have my score increasing by distance of 1 every 1 unit traveled, works no problem. Now I have a coin object for the player to collect, which I want to add 10 points to the current score accumulated. I’ve spent longer than I’d liked to admit on this simple problem. I’m newer to code and unity. Below is my two scripts for the ScoreManager and Coin object.

public class ScoreManager : MonoBehaviour
{
    public Transform player;
    public Text scoreText;
    public  int score = 0;
    private int distanceScore = 0;

    // Distance variables
    Vector3 previousPosition;
    float calculatedDistance;

    // Start is called before the first frame update
    void Awake()
    {

        previousPosition = player.position;
        
    }

    // Update is called once per frame
    void Update()
    {
        calculatedDistance += (player.position - previousPosition).magnitude;
        previousPosition = player.position;
        distanceScore = Mathf.RoundToInt(calculatedDistance);
        score = distanceScore;
        scoreText.text = "Score: " + score;

    }
}


public class Coin : MonoBehaviour
{
    private int coinScore = 10;
    public ScoreManager sm;

    // Start is called before the first frame update
    void Start()
    {
        
    }

    // Update is called once per frame
    void Update()
    {
        transform.Rotate(90 * Time.deltaTime, 0, 0);
    }

    private void OnTriggerEnter(Collider other)
    {
       
        if (other.name == "Car")
        {
            
            Destroy(gameObject); // Destroy coin 
            sm.score = +coinScore;       
        }   
    }
}
2

This is because you are overwriting your score value every update, so even if you add some value based on picking up a coin it will be overwritten by the distance score only on the next frame. Try something like this instead → 

calculatedDistance += (player.position - previousPosition).magnitude;
previousPosition = player.position;
distanceScore = Mathf.RoundToInt (calculatedDistance);
score += distanceScore;
calculatedDistance -= distanceScore;

Now instead of overwriting the score value with the distance every frame, you are just adding to it. Then you just need to subtract from your distance every time you increase the score.