8 Essential Java Data Structures

Eight common data structures in Java include:

1. Array: a collection of elements with the same type.
2. Linked List: A collection of nodes, where each node contains a data element and a reference to the next node.
3. Stack: A data structure that follows the Last-In-First-Out (LIFO) principle, where only one end can perform insertions and deletions.
4. Queue is a data structure that follows the First-In-First-Out (FIFO) principle, where items are inserted at one end and removed from the other end.
5. Tree: a hierarchical structure composed of nodes, each of which can have multiple child nodes.
6. Graph: a collection of nodes and edges, where nodes represent objects and edges represent the relationships between nodes.
7. Heap: a special type of tree data structure where the value of any node is greater than or equal to (or less than or equal to) the values of its child nodes.
8. Hash Table: a data structure that allows for direct access to data based on a key, by mapping the key to a fixed position.

The above are common data structures that are suitable for various scenarios and problem-solving.