- coins

Unity Engine
1

I have a problem with the number of coins when I have 0 coins my number of coins goes negative
I would buy only if I had the cost

using UnityEngine;
using UnityEngine.UI;
using System.Collections;
public class HandleBasket : MonoBehaviour
{
    public int cost = 0;
    private Image image;
    private Button button;
    private bool enable = false;
    private CoinCounter coinCounter;
    void Start()
    {
        image = GetComponent<Image>();
        button = GetComponent<Button>();
        coinCounter = GameObject.Find("CoinCount").GetComponent<CoinCounter>();
        enable = PlayerPrefs.GetInt(gameObject.tag, 0) == 1;
    }
    void Update()
    {
        Color c = image.color;
        if (enable)
        {
            c = Color.yellow;
        }
        else
        {
            if (coinCounter.coinCount >= cost)
            {
                c.a = 1;
            }
            else
            {
                c.a = 0.1f;
            }
        }
        image.color = c;
    }
    public void buy()
    {
        if (enable)
        {
            return;
        }
      
        coinCounter.coinCount -= cost;
        enable = true;
    }
    void OnDestroy()
    {
        PlayerPrefs.SetInt(gameObject.tag, enable ? 1 : 0);
        PlayerPrefs.Save();
    }
}
2

Like this?

if(coinCounter.coinCount >= cost){
coinCounter.coinCount -= cost;
}
3

I would disable the button if i hadn’t enough money