Build Your Own JSON Parser
Build a fully RFC 8259-compliant JSON parser from scratch. You'll tokenize structural characters, decode escape sequences and Unicode, parse numbers with strict grammar, and recursively assemble objects and arrays. By the end you'll deeply understand how json.loads, JSON.parse, and every other parser actually works.
beginner12 lessons4 chapters12 graded exercisesPython
No sign-up needed for lesson 1 · certificate on completion · sign up to save progress
What you’ll have built
Chapter by chapter. Every step is a graded exercise.
- Tokenizing JSON
- Parsing Values
- Containers: Arrays & Objects
- Production Concerns
Starts in Python — solve in the language you choose in the editor, same tests either way.
Curriculum
4 chapters, 12 lessons. Each lesson is a short read, one graded exercise, and a quiz.
- 1Tokenizing JSONRead · exercise · quiz
- 2String Escape SequencesRead · exercise · quiz
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