Common and Essential Data Structures in Java

There are several data structures in the Java course; you must learn about them if you want to crack the coding interviews. Most candidates today are pretty good at using programming for everyday life research problems. It would be best if you brushed up on the basics of various structures in the coding interview, as most of the issues will revolve around choosing the proper structure for the given problem. Under this article, you can get your hands on the data structures in the Java course.

Some of the most common and essential data structures in Java


List features the value sequence in the ordered fashion, which would be placed in memory adjacent. The address of the first element would identify the list. The placement order of the elements makes a list in the memory which follows the same order in which they would be defined. So irrespective of the position, each element in the list will take time constantly, and it can be accessed by enhancing the address of the first element by the perfect index amount.

Linked list

A linked list is different from a List, and it does not have the order defined by the physical placement of the memory. Instead, each linked list element features the address and the values to the following link of the element listed. Hence you can say that the linked list can be traversed sequentially, going through every element simultaneously. It also means that the length of the linked list can only be known after completing the traversing of the element by element. The last element of the linked list does not have any pointers.

Hash tables

The hash tables would be considered a general list form. You have to map the indices to the values that can be accessed constantly. Hash tables map a data type to another data type so the pairs can be accessed constantly. For every pair, the key is passed through the hash function to create a unique physical address for the value that would be stored in the memory. The hash function would be created for a unique physical address across the fundamental values most of the time. At times the hash function can come up with generating a similar physical address for different keys. It is known as a collision.


It is a data structure featuring a sequence that will maintain the element order as they were inserted firstly in the queue. It features the first in, first out method, which means the elements would be accessed in a similar order that was firstly inserted in the queue. The first one we removed will be the one that was inserted first. You need to understand two positions placed horizontally to understand the working of the Queue.


Stack is also a type of sequential structure of the data where all the element’s order is maintained as they are inserted, and it is very different from the queue because it follows the last in, first out method. It means that the first element to be removed will be inserted last.

Hence these are some commonly used data structures for the coding interview.