Variable Lifespan

Unity Engine
1

Hi All,

Had a few questions regarding Variable Lifespan. Let’s assume I have the following:

Scene 1 - Main Menu
Scene 2 - Play Board

My questions revolve around what happens to variables during scene changes.

For example. Let’s say I click play on scene 1 and now load Scene 2. Scene 2 sets variables etc, allocates an array at the top of a script for the play board etc.

When I leave Scene 2 and go back to Scene 1 after playing, are all my variables still around, or has garbage collection removed them?

If I then click play again on Scene 1 and load scene 2, am I now allocating a second set of variables, such as an array that I load information into?

Do all the events like Awake, Start, etc all get sent again if it is the second time I am now loading Scene 2?

Is there something special I should do when leaving a scene or loading a scene to ensure I am not allocating space for the same variable twice (aka the second time into Scene 2 when I load it).

Thanks for all the help

Chris

2

PlayerPrefs or DontDestroyOnLoad()

easy as pie or cake which ever you prefer

3

PlayerPrefs really shouldn’t ever be used for communicating variables between scenes. It’s slow. It slows down legitimate PlayerPref use (AFAIK, every insertion/edit into PlayerPrefs takes a time proportionate to how many keys are stored in it already). It adds a negligible amount of HD use for stand-alones, but for web-players, you have the possibility of a PlayerPrefs Exception. It’s easier to have initialization errors. There isn’t any name-spacing. PlayerPrefs should only be used to communicate data between sessions.

Don’tDestroyOnLoad() is great though. Singletons are also a great solution.

Opening a scene for a second time is the same as opening it for the first time.