Memory Management for performance

[korgoth]

What are the best practices for memory management? For example I have a game with a lot of assets ( images,tilemaps,sound ) and a lot of states ( game, menu,level select, world select, etc ).

1. how to handle asset loading?
  a.: load every asset with the preloader state
  b.: use the preload method on every states and load only the required assets
 
2. if the "b" method is better, do I need to clear the assets from the Cache when I switch states? For example I load a,b,c image for StateA then load d,e,f image for StateB. The a,b,c images still in the memory when the StateB active. And if I switch to StateC and load g,h,i images the a,b,c,d,e,f images are still in the memory. Or performance not depends on the cached objects?

3. do I need to destroy every created object in the shutdown method?
   for example in the create method:
  

this.sprite = this.add.sprite();this.group = this.add.group();

   in the shutdown:

this.sprite.destroy();this.group.destroy();

   
4. what about local variables? like:  var sprite = this.add.sprite();  how to destory them? Do i need to add every local object to a group and destory that?
 

[stasuss]

As for the preloading of the assets, I think, it is about what do you wish to save - network traffic or memory.

As for sprites - I think it is better to use the recycling. No need to destroy everything. They aren't using very mush memory.