While in this lecture the singelton functions, if you use it in other games it may not for some reason. Instead of useing if(instance != null), use if(instance != null && instance != this). That prevents weird problems.
While in this lecture the singelton functions, if you use it in other games it may not for some reason. Instead of useing if(instance != null), use if(instance != null && instance != this). That prevents weird problems.