Text & Data

What you'll learn

• Read and write JSON without losing data along the way
• Build regular expressions that match what you mean
• Reason about floating-point numbers and when precision bites
• Handle dates without falling into timezone traps
• Format numbers, dates, currency, and lists for any locale
• Move between strings, bytes, and base64 with confidence

1. 01
   JSON in earnest

   The four shapes JSON allows, what stringify quietly drops, and how replacer and reviver let you fix it.
   14 min
2. 02
   Regular expressions, the basics

   Character classes, quantifiers, anchors, and the flags you actually reach for.
   17 min
3. 03
   Regex in practice

   Capture groups, named groups, lookarounds, and the methods that pull text apart and put it back together.
   17 min
4. 04
   Numbers and Math

   Why 0.1 + 0.2 isn't 0.3, where integers stop being safe, and the Math methods worth knowing.
   15 min
5. 05
   Dates with Date

   Milliseconds since 1970, the timezone trap, and why parsing a date string is rarely what you want.
   15 min
6. 06
   Temporal, briefly

   A preview of the date API JavaScript should have shipped with: PlainDate, Instant, Duration.
   11 min
7. 07
   Internationalization

   Format currency, dates, lists, and plurals for any locale with the Intl objects already in your runtime.
   17 min
8. 08
   Encoding text and bytes

   What UTF-8 actually is, how to move between strings and Uint8Array, and the base64 footgun nobody warns you about.
   19 min