What are the uses of a Java ArrayList?

ArrayList is one of the commonly used collection classes in Java, mainly used for the following purposes:

1. Storing and manipulating data: ArrayList can store objects of any type, elements can be added using the add() method, retrieved using the get() method, deleted using the remove() method, making it easy to store and operate data.
2. Dynamic growth: The capacity of an ArrayList grows dynamically, automatically increasing when the capacity is exceeded, allowing elements to be added or removed as needed without having to specify a capacity beforehand.
3. Alternative to arrays: ArrayList can be seen as a replacement for arrays. Compared to arrays, ArrayList has more functionality and flexibility. It can dynamically change in size and provides more methods for manipulating elements.
4. Traversal and searching: ArrayList offers methods for traversing and searching elements, such as using a for-each loop to iterate through all elements, using the contains() method to determine if a certain element is included, and using the indexOf() method to find the position of an element.

It is important to note that ArrayList is implemented based on an array, using an array to store elements. Therefore, when inserting or deleting elements, it may involve moving array elements. Additionally, ArrayList is not thread-safe and should not be used in a multi-threaded environment. If thread safety is needed, consider using thread-safe collection classes like Vector or CopyOnWriteArrayList.