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JavaScript Practice Challenges

A page for every one of the 307 JavaScript solutions, numbered 000-306. Each entry contains the current implementation, its inline assertions, a link to the executable source and a command for running that exercise.

Solution catalog

• Exercises 000-099
• Exercises 100-199
• Exercises 200-299
• Exercises 300-306

Getting started

Clone the repository and use Node.js matching ^20.19.0 || ^22.13.0 || >=24 (the runtime requirement of ESLint 10).

git clone https://github.com/haribo841/JavaScript-Practice-Challenges.git
cd JavaScript-Practice-Challenges
npm ci
npm run check

npm run lint checks JavaScript with ESLint. npm test first runs the worker-pool regression tests, then executes all 307 exercise files in separate Node.js processes, with a five-second timeout per file and at most four processes active at once. Reporting follows filename order even when processes finish in a different order. Assertions throw on failure, and any failed exercise makes the test command fail.

Testing and tooling explains individual runs, runtime requirements and verification limits.

Reference material

The original wiki pages are retained in the historical archive. Matching study notes appear in clearly labelled historical sections. They can describe a different language or numbering scheme and are not a JavaScript benchmark.

Duplicate exercise topics keep their original numbers. In particular, 132 and 306 are separate first-truthy exercises; neither is removed. Entry 000 documents its actual greeting implementation despite the old filename.

Repository | ESLint configuration | Report an issue

Repository guide

Getting started | Project map and checks | Sources, attribution and reuse