How to run a update function once

Questions & Answers
1

I have this code

public float speed;
// Start is called before the first frame update
void update()
{
    if (Score.score > 2)
    {
        speed = 4;
        KillPipes();
    }
    if(Score.score > 50)
    {
        speed = 5;
    }
    if(Score.score > 100)
    {
        speed = 6;
    }
}

I only need this to run once, and then delete or disable the code, how can I do that?

2

If you put the update function in a script and that script does not get destroyed after the first time it runs, it will continue. I think you are potentially looking for behaviour that can be provided by a coroutine:

void Start(){
    StartCoroutine(OneUpdate());
}

IEnumerator OneUpdate(){

    yield return new WaitForEndFrame();
    
    //Your logic 
}
3

It is not clear what the question asks for.

The Start() method runs only once anyway.

If you want to destroy the script after execution you can write:

void Start(){
     //Start Code
     Destroy(this); //Destroys this script
 }

If you want to destroy the gamObject after execution write:

void Start() {
     //Start Code
     Destroy(gameObject);
}
4

You can use enabled = false but it will disable the script and the update function will not be called unless you enable it again by another script.

    private void Update()
    {
        if (score > 2)
        {
            speed = 4;
            KillPipes();
            enabled = false;
        }
        // This code will not reach beyond this line 
        if (score > 50)
        {
            speed = 5;
        }

        if (score > 100)
        {
            speed = 6;
        }
    }