Handle Unicode text, emoji, encoding, normalization, code points, and safe storage.
Lessons
Letters, marks, numbers, punctuation, and symbols.
Unicode Character Categories is easiest to learn by reading the example, changing it, and observing the result.
// Unicode is organized into 17 planes of 65,536 code points each.
// Plane 0 (BMP) U+0000–U+FFFF most living-language characters
// Plane 1 (SMP) U+10000+ emoji, historic scripts, symbols
const samples = { latin: 'A', greek: 'Ω', cjk: '日', emoji: '😀' };
for (const [name, ch] of Object.entries(samples)) {
const cp = ch.codePointAt(0);
console.log(name, 'U+' + cp.toString(16).toUpperCase(),
cp > 0xFFFF ? '(supplementary)' : '(BMP)');
}Practice the Unicode Character Categories example in a small scratch file, then explain what changed and why.