String interning is a method of storing only one copy of each distinct string value, which must be immutable. The distinct values are stored in a string intern pool. The single copy of each string is called its 'intern' and is typically looked up by a method (e.g. String.intern() in Java.).
We have discussed the theory about access modifiers in the previous note. This note will give you an example code that will show the valid and invalid usages for members belonging to different access levels from different regions of your code such as same class, subclass in same package, subclass in another package and a non-subclass in another package.