Bits of .NET

🌍 No More Moment.js

Dates, numbers, currencies, plurals — all have different formats per locale. Intl API is built-in. No libraries needed.

📝 Date Formatting

const date = new Date();

// US English
new Intl.DateTimeFormat('en-US').format(date);
// "12/31/2024"

// UK English
new Intl.DateTimeFormat('en-GB').format(date);
// "31/12/2024"

// German
new Intl.DateTimeFormat('de-DE').format(date);
// "31.12.2024"

// Japanese
new Intl.DateTimeFormat('ja-JP').format(date);
// "2024/12/31"

// With options
new Intl.DateTimeFormat('en-US', {
  weekday: 'long',
  year: 'numeric',
  month: 'long',
  day: 'numeric'
}).format(date);
// "Tuesday, December 31, 2024"

// Relative time
const rtf = new Intl.RelativeTimeFormat('en', { numeric: 'auto' });
rtf.format(-1, 'day');   // "yesterday"
rtf.format(2, 'day');    // "in 2 days"
rtf.format(-3, 'week');  // "3 weeks ago"

💰 Number & Currency Formatting

const price = 1234.56;

// US Dollar
new Intl.NumberFormat('en-US', {
  style: 'currency',
  currency: 'USD'
}).format(price);
// "$1,234.56"

// Euro (German)
new Intl.NumberFormat('de-DE', {
  style: 'currency',
  currency: 'EUR'
}).format(price);
// "1.234,56 €"

// Japanese Yen (no decimals)
new Intl.NumberFormat('ja-JP', {
  style: 'currency',
  currency: 'JPY',
  minimumFractionDigits: 0
}).format(price);
// "￥1,235"

// Percentage
new Intl.NumberFormat('en-US', {
  style: 'percent',
  minimumFractionDigits: 1
}).format(0.1234);
// "12.3%"

// Compact notation (1K, 1M)
new Intl.NumberFormat('en-US', {
  notation: 'compact',
  compactDisplay: 'short'
}).format(1234567);
// "1.2M"

✅ String Operations

// Plurals (German example)
new Intl.PluralRules('de').select(0);   // "zero"
new Intl.PluralRules('de').select(1);   // "one"
new Intl.PluralRules('de').select(2);   // "other"

// List formatting
const listFormatter = new Intl.ListFormat('en', {
  style: 'long',
  type: 'conjunction'
});
listFormatter.format(['Apple', 'Banana', 'Orange']);
// "Apple, Banana, and Orange"

// Sort strings (respects language)
const words = ['café', 'apple', 'banana', 'éclair'];
words.sort(new Intl.Collator('fr').compare);
// French sorting: apple, banana, café, éclair

// Segmenter (split by word/sentence)
const segmenter = new Intl.Segmenter('en', { granularity: 'word' });
const segments = segmenter.segment('Hello world');
for (let seg of segments) {
  console.log(seg.segment);
}

💡 Benefits

• No external libraries (moment.js, numeral.js) → smaller bundle
• Native performance (C++ implementation)
• Supports 100+ languages
• Automatic locale detection: navigator.language