Spawn a single object in Unity on click

Question

I want to spawn a single game object either when I click on the screen. I have tried using loop but still it instantiate more than one time. Here I have used other loop too and tried to put it in Start method too... I have followed many youtube video but couldn't get the desired output.

[SerializeField]
GameObject spawnObject;

void Update()
{
    for (int i = 0; i < 1; i++)
    {
        if (Input.GetMouseButtonDown(0))
        {
            Vector3 touchPos = Camera.main.ScreenToWorldPoint(Input.mousePosition);
            GameObject g = Instantiate(spawnObject, (Vector2)touchPos, Quaternion.identity);
            //Debug.Log(i);
            Debug.Log(Input.mousePosition);
        }
    }
}

Help me out...

Answer 1

If you want to limit this for the entire live time of the application

• Either simply add a flag like

  [SerializeField]
  GameObject spawnObject;
  
  private static bool wasSpawned;
  
  void Update()
  {
      if (!wasSpawned && Input.GetMouseButtonDown(0))
      {
          Vector3 touchPos = Camera.main.ScreenToWorldPoint(Input.mousePosition);
          GameObject g = Instantiate(spawnObject, (Vector2)touchPos, Quaternion.identity);
          Debug.Log(Input.mousePosition);
  
          wasSpawned = true;
      }
  }
  

• or you could as well simply deactivate/destroy this component so it isn't further executed at all which would even slightly save some resources

  [SerializeField]
  GameObject spawnObject;
  
  void Update()
  {
      if (Input.GetMouseButtonDown(0))
      {
          Vector3 touchPos = Camera.main.ScreenToWorldPoint(Input.mousePosition);
          GameObject g = Instantiate(spawnObject, (Vector2)touchPos, Quaternion.identity);
          Debug.Log(Input.mousePosition);
  
          // destroys only this component, not the entire GameObject 
          Destroy(this);
          // alternatively destroy entire GameObject
          //Destroy(gameObject);
          // alternatively only disable in case needed again later
          //enabled = false;
      }
  }