Javascript check if score is adding

Unity Engine
1

This may sound like a silly question and it may well be i have been behind the screen for too long.

How do i create an if statement which checks if score is adding.

if(score has added one point)
{
run this once;
}
else if (score has subtracted)
{
run this once;
}

2

You’re going to need to keep track of the previous score somewhere.

private int _previousScore;
private int _currentScore;

void Start() {
    this._previousScore = 0;
    this._currentScore = this._previousScore;
}

//amount can be negative for subtracting points
void ChangeScore(int amount) {
    this._previousScore = this._currentScore;
    this._currentScore += amount;
}

void Update() {
    if (this._previousScore > this._currentScore) {
        //score subtracted points
    }
    else if (this._previousScore < this._currentScore) {
        //score added points
    }
    else {
        //score was not changed
    }
}