This article explains how to implement some data structures in Java. It will be useful for beginners that use a programming language Java, as well as those who already know how to write a new ArrayList (), but have little knowledge what is happening inside.
Let us talk about the ArrayLists
ArrayList implements the List interface. As we know, Java arrays have a fixed length, and after the array is created, it cannot increase or decrease. ArrayList can change its size at runtime, but it does not necessarily indicate the size when an object is created. The elements of ArrayList can be any types, including null.