Unity(C#) — How to fix change of value by variable in Update?

Question

C++ / C#

When a variable (int) changes its value, I need to call a method that will work 1 time in Update.

Answer 1

private int oldValue;

void Start() 
{
    oldValue = 42
}

void Update()
{
    if (oldValue != newValue)
    {
        OnValueChanged(newValue);
        oldValue = newValue;
    }
}

private void OnValueChanged(int newValue) 
{
}

But in general it is better to look towards events and delegates, or even (especially if there are many such places) Unity Atoms .