Number Utilities

const formatCurrency = (amount, currency = "USD", locale = "en-US") =>
  new Intl.NumberFormat(locale, { style: "currency", currency }).format(amount);

formatCurrency(1234567.89);           // "$1,234,567.89"
formatCurrency(1234567.89, "EUR", "de-DE"); // "1.234.567,89 €"
formatCurrency(1500, "INR", "en-IN");  // "₹1,500.00"
formatCurrency(9.99, "GBP", "en-GB"); // "£9.99"

const formatNumber = (n, decimals = 0, locale = "en-US") =>
  new Intl.NumberFormat(locale, { minimumFractionDigits: decimals, maximumFractionDigits: decimals }).format(n);

formatNumber(1234567);       // "1,234,567"
formatNumber(1234567.891, 2); // "1,234,567.89"
formatNumber(0.5, 1);         // "0.5"

const formatBytes = (bytes, decimals = 2) => {
  if (bytes === 0) return "0 Bytes";
  const k = 1024;
  const sizes = ["Bytes", "KB", "MB", "GB", "TB", "PB"];
  const i = Math.floor(Math.log(bytes) / Math.log(k));
  return `${parseFloat((bytes / Math.pow(k, i)).toFixed(decimals))} ${sizes[i]}`;
};

formatBytes(0);            // "0 Bytes"
formatBytes(1024);         // "1 KB"
formatBytes(1048576);      // "1 MB"
formatBytes(1073741824);   // "1 GB"
formatBytes(1500, 1);      // "1.5 KB"

const formatCompact = (n, locale = "en-US") =>
  new Intl.NumberFormat(locale, { notation: "compact", compactDisplay: "short" }).format(n);

formatCompact(1000);        // "1K"
formatCompact(1500);        // "1.5K"
formatCompact(1000000);     // "1M"
formatCompact(2500000);     // "2.5M"
formatCompact(1000000000);  // "1B"

const clamp = (value, min, max) => Math.min(Math.max(value, min), max);

clamp(15, 0, 10);   // 10
clamp(-5, 0, 10);   // 0
clamp(5, 0, 10);    // 5

const randomInt = (min, max) =>
  Math.floor(Math.random() * (max - min + 1)) + min;

randomInt(1, 6);    // dice roll: 1–6
randomInt(0, 100);  // 0–100

const randomFloat = (min, max, decimals = 2) =>
  parseFloat((Math.random() * (max - min) + min).toFixed(decimals));

randomFloat(0, 1);       // 0.73 (random)
randomFloat(1.5, 3.5, 1); // 2.4 (random)

const lerp = (start, end, t) => start + (end - start) * t;

lerp(0, 100, 0.5);   // 50
lerp(10, 20, 0.25);  // 12.5
lerp(0, 255, 1);     // 255

const isEven = (n) => n % 2 === 0;
const isOdd  = (n) => n % 2 !== 0;

isEven(4); // true
isOdd(7);  // true

const toOrdinal = (n) => {
  const s = ["th", "st", "nd", "rd"];
  const v = n % 100;
  return n + (s[(v - 20) % 10] || s[v] || s[0]);
};

toOrdinal(1);   // "1st"
toOrdinal(2);   // "2nd"
toOrdinal(3);   // "3rd"
toOrdinal(11);  // "11th"
toOrdinal(21);  // "21st"
toOrdinal(42);  // "42nd"

const percentage = (part, total, decimals = 1) =>
  `${((part / total) * 100).toFixed(decimals)}%`;

percentage(25, 200);     // "12.5%"
percentage(1, 3, 2);     // "33.33%"
percentage(750, 1000);   // "75.0%"

const roundTo = (n, decimals) =>
  Math.round(n * 10 ** decimals) / 10 ** decimals;

roundTo(1.2345, 2);  // 1.23
roundTo(1.005, 2);   // 1.01
roundTo(123.456, 0); // 123