JSON and data formats

Know what a format can hold, and stop losing data in the gaps between them.

For anyone moving data between systems — developers, analysts, anyone who has opened an export and found it mangled. Some programming background helps; the traps are language-independent.

4 lessons · about 10 minutes

Start: What JSON can and cannot hold

Practise all 8 questions

  1. What JSON can and cannot holdSix types, no comments, no dates — and everything else is a convention on top.2 min
  2. Numbers: where precision goesJSON numbers are doubles in practice, and that quietly breaks ids and money.2 min
  3. YAML and CSV: the same data, different trapsYAML guesses types and CSV has no types at all.3 min
  4. Reading data you did not writeParsing succeeds far more often than the data is usable, and the gap is where bugs live.3 min