datastructures-algorithms is a table of implementations you can run in the browser

Every entry is a folder with a number and a technique name

The organising idea is visible in the file paths. A stack implemented with an array lives at a path that encodes the section, the technique and the number.

src/javascript/datastructures/stack/1.stack_with_array/stack_with_array.js

The same pattern holds for the linked list version of the stack and for the queue, where the array implementation sits in 1.queue_with_array and the linked list one in 2.queue_with_linkedlist. That naming does two jobs. It makes the ordering explicit, so a reader opening the directory sees the alternatives in a fixed sequence, and it names the technique in the folder rather than leaving it to the file, which matters because the whole point of having two implementations of a stack is that they are different techniques with different trade-offs. A SinglyLinkedList implementation and a DoublyLinkedList implementation are separate entries in the same way, and the two are distinct data structures rather than variations of one.

The table columns are a syllabus disguised as a spreadsheet

Each row of the README table carries the same set of columns, and reading them across is a better description of the repository than any paragraph could be. There is a number, a name, a Source link, a Live link, a Documentation link, a Level, a Pattern and a Hint. The Level column marks an entry as Easy in the examples given. The Pattern column names the technique being demonstrated, so the stack using an array is listed as Using Array operations and the linked list version as Using LinkedList operations. The Hint column is the most useful of the three for a learner, because it gives the one line approach in the form of a directive: use array push/pop for stack behaviour, use linked list nodes for stack push/pop, use array shift/unshift or a circular buffer for the queue, and maintain head and tail pointers for enqueue and dequeue. It is the kind of hint that lets you attempt the exercise before you read the solution, which is the difference between a reference and a course.

Live links mean you can run an example without a local setup

The Live column points at a playground that opens the source file directly in a console, with the file content carried in the URL. The README describes the repository as containing an interactive playground where available, alongside source code and documentation explaining the concept, the approach and the complexity. That last part matters, because the documentation is per entry rather than a single long article, so the explanation of a circular buffer sits next to the circular buffer rather than in a chapter you have to find. The arrangement also means the examples are meant to be read and modified rather than installed. The Documentation column is not populated for every row, the stack entries show a dash in the README, while the queue and the singly linked list do carry documentation links, so the depth of prose support varies from entry to entry and that is worth checking before you settle in to a particular topic.

JavaScript first, with the other languages as exceptions

The README says the implementations are primarily in JavaScript, with some examples in other languages like Java, TypeScript and Go. The repository topics back that up, listing java and javascript as the two language tags, and also carrying the topic tags that suggest what is inside, from algorithm-challenges, leetcode and interview through dsa and dynamic-programming, and then the specific structures, graph, linkedlist, queue, stack and tree. There are also tags for lodash, polyfills and prototype, which points to a set of JavaScript specific exercises about language behaviour rather than about classic computer science, and the polyfills angle in particular is a different topic from the rest of the list. The repository layout is mostly under src/, with a language directory and then the category, and the one file sitting at the repository root rather than under src/ is a Java program for the cheapest flight problem using the K hops algorithm, which is an outlier in an otherwise JavaScript shaped tree.

The scope is broad enough that it is a catalogue, not a course

Here is the honest limitation. The README describes the repository as a comprehensive collection of data structures and algorithms implemented in multiple programming languages and as a resource for learning and practising fundamental computer science concepts, and the tag list covers a wide surface, but a table of this shape is a catalogue of topics rather than a sequenced course. There is no stated order to work through it, no project that pulls several structures together, and no stated difficulty progression beyond the per entry level. So a reader who wants a curriculum will find a good index and will still have to choose the path. The other limitation follows from the format. Every entry is a small standalone program with its own documentation file, and a standalone program is not the same as a tested, reusable implementation, so the code is good for reading and for practising and is less good as a foundation for a production data structure, where you would want a maintained library with a stated API, error handling and type definitions.

Editorial conclusion

datastructures-algorithms suits a developer who wants to see the same data structure built more than one way, since the stack section alone offers an array implementation and a linked list implementation side by side with a hint for each, and it suits anyone who prefers clicking a live link to reading a file. It is the wrong tool if you want a library you can import, because the repository is a collection of programs rather than a published package, and it is the wrong tool for a project with a language requirement other than JavaScript, since the implementations are primarily in JavaScript with only some examples elsewhere. Before working through it, pick the language you want to learn in and check that the corresponding folder exists, since the table rows are mostly JavaScript, and note that the repository has no releases and an empty licence field, so copy the code rather than depending on it. The last push was on 2026-10-10.

Frequently asked questions

Official sources

1. Issues
2. README
3. sudheerj/datastructures-algorithms on GitHub