Note the following when using Node userObject instance variables in Cocos2D:

Note the following when using Node userObject instance variables in Cocos2D:

 

We know that in Cocos2D, The CCNode object has an ivar as userObject, which can be used to conveniently store data related to this object, in this way, you do not have to bother writing subclass inheritance.

However, if your node is added to a node as a subclass, for example:

[SomeBaba addChild: myNode];

When the following statement is called to delete myNode from the parent node, the userObject will also be cleared:

[MyNode removeFromParent]; // some code use myNode. userObject, ERROR !!! // MyNode. userObject now is nil !!!

As shown above, after deleting itself from the parent node, although myNode itself has not been deleted (because it is still referenced elsewhere), its userObject content is already nil.
Therefore, you may want to delete the parent node before using it. In this case, you can:

Id tmpObj = myNode. userObject; [myNode removeFromParent]; // that's OK to use tmpObj now :)