Data hiding concept, private data member of a Java class described with the help of a Java array, where an array declared as private member inside a Java class. So you cannot access the array elements inside Java class directly. You can insert integers in the array, delete array elements (which are integers) and get element from the array in Java with the help of getter and setter methods. Deletion of array element needs shifting of elements because it creates a vacancy inside array. A practical example of data hiding w.r.t array as private data member inside a Java class.
Learn what are Java interfaces, and how multiple inheritance is incorporated in Java with the help of Java interfaces.
Learn Java multithreading and concurrency. Learn about Java thread states and different steps of multithreading with simple examples.