Handle Unicode text, emoji, encoding, normalization, code points, and safe storage.
Lessons
Understand the BMP and supplementary planes.
Unicode Planes & Blocks 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 Planes & Blocks example in a small scratch file, then explain what changed and why.