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feat: added formatNumber util
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‎README.md‎

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@@ -67,6 +67,43 @@ extractYouTubeVideoID("https://www.youtube.com/watch?v=JWJz_MS1-I8&t=1815s"); //
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extractYouTubeVideoID("https://youtu.be/JWJz_MS1-I8"); // JWJz_MS1-I8
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```
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### `formatNumber`
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Formats numbers into human-readable strings with appropriate unit suffixes (k, m, b).
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**Usage:**
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```typescript
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import { formatNumber } from "largs-utils";
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// Thousands
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formatNumber(1000); // "1k"
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formatNumber(1500); // "1.5k"
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formatNumber(45678); // "45.7k"
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// Millions
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formatNumber(1000000); // "1m"
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formatNumber(2500000); // "2.5m"
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formatNumber(1234567); // "1.2m"
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// Billions
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formatNumber(1000000000); // "1b"
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formatNumber(5500000000); // "5.5b"
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// Regular numbers (less than 1000)
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formatNumber(999); // "999"
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formatNumber(123); // "123"
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// Custom decimal precision
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formatNumber(1234, 0); // "1k"
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formatNumber(1234, 1); // "1.2k"
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formatNumber(1234, 2); // "1.23k"
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// Negative numbers
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formatNumber(-1500); // "-1.5k"
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formatNumber(-2500000); // "-2.5m"
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```
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### `generatePrefixedId`
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Generates UUID with a prefix

‎src/__tests__/formatNumber.test.ts‎

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import { formatNumber } from "../formatNumber";
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describe("formatNumber", () => {
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describe("billions formatting", () => {
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it("should format billions with 'b' suffix", () => {
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expect(formatNumber(1000000000)).toBe("1b");
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expect(formatNumber(1500000000)).toBe("1.5b");
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expect(formatNumber(2300000000)).toBe("2.3b");
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});
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it("should format large billions correctly", () => {
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expect(formatNumber(15000000000)).toBe("15b");
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expect(formatNumber(999999999999)).toBe("1000b");
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});
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});
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describe("millions formatting", () => {
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it("should format millions with 'm' suffix", () => {
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expect(formatNumber(1000000)).toBe("1m");
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expect(formatNumber(1500000)).toBe("1.5m");
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expect(formatNumber(2300000)).toBe("2.3m");
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});
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it("should format large millions correctly", () => {
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expect(formatNumber(999000000)).toBe("999m");
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expect(formatNumber(500000000)).toBe("500m");
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});
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});
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describe("thousands formatting", () => {
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it("should format thousands with 'k' suffix", () => {
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expect(formatNumber(1000)).toBe("1k");
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expect(formatNumber(1500)).toBe("1.5k");
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expect(formatNumber(2300)).toBe("2.3k");
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});
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it("should format large thousands correctly", () => {
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expect(formatNumber(999000)).toBe("999k");
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expect(formatNumber(500000)).toBe("500k");
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});
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});
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describe("regular numbers", () => {
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it("should format numbers less than 1000 without suffix", () => {
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expect(formatNumber(0)).toBe("0");
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expect(formatNumber(1)).toBe("1");
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expect(formatNumber(100)).toBe("100");
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expect(formatNumber(999)).toBe("999");
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});
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it("should handle decimal numbers less than 1000", () => {
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expect(formatNumber(1.5)).toBe("1.5");
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expect(formatNumber(99.9)).toBe("99.9");
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expect(formatNumber(123.456)).toBe("123.5");
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});
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});
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describe("decimal precision", () => {
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it("should respect custom digits parameter", () => {
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expect(formatNumber(1234, 0)).toBe("1k");
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expect(formatNumber(1234, 1)).toBe("1.2k");
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expect(formatNumber(1234, 2)).toBe("1.23k");
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expect(formatNumber(1234, 3)).toBe("1.234k");
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});
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it("should handle precision for millions", () => {
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expect(formatNumber(1234567, 0)).toBe("1m");
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expect(formatNumber(1234567, 1)).toBe("1.2m");
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expect(formatNumber(1234567, 2)).toBe("1.23m");
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});
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it("should handle precision for billions", () => {
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expect(formatNumber(1234567890, 0)).toBe("1b");
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expect(formatNumber(1234567890, 1)).toBe("1.2b");
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expect(formatNumber(1234567890, 2)).toBe("1.23b");
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});
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});
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describe("trailing zeros cleanup", () => {
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it("should remove trailing zeros after decimal", () => {
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expect(formatNumber(1000)).toBe("1k");
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expect(formatNumber(2000000)).toBe("2m");
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expect(formatNumber(3000000000)).toBe("3b");
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});
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it("should keep significant decimals and remove trailing zeros", () => {
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expect(formatNumber(1100, 2)).toBe("1.1k");
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expect(formatNumber(1010, 2)).toBe("1.01k");
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expect(formatNumber(1001, 3)).toBe("1.001k");
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});
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});
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describe("negative numbers", () => {
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it("should handle negative thousands", () => {
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expect(formatNumber(-1000)).toBe("-1k");
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expect(formatNumber(-1500)).toBe("-1.5k");
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});
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it("should handle negative millions", () => {
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expect(formatNumber(-1000000)).toBe("-1m");
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expect(formatNumber(-2500000)).toBe("-2.5m");
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});
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it("should handle negative billions", () => {
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expect(formatNumber(-1000000000)).toBe("-1b");
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expect(formatNumber(-5500000000)).toBe("-5.5b");
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});
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it("should handle negative numbers less than 1000", () => {
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expect(formatNumber(-1)).toBe("-1");
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expect(formatNumber(-100)).toBe("-100");
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expect(formatNumber(-999)).toBe("-999");
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});
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});
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describe("edge cases", () => {
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it("should handle zero", () => {
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expect(formatNumber(0)).toBe("0");
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expect(formatNumber(-0)).toBe("0");
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});
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it("should handle very small numbers", () => {
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expect(formatNumber(0.1)).toBe("0.1");
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expect(formatNumber(0.01)).toBe("0");
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});
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it("should handle numbers just below thresholds", () => {
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expect(formatNumber(999)).toBe("999");
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expect(formatNumber(999999)).toBe("1000k");
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expect(formatNumber(999999999)).toBe("1000m");
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});
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});
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describe("invalid inputs", () => {
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it("should return '0' for NaN", () => {
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expect(formatNumber(NaN)).toBe("0");
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});
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it("should return '0' for non-number types", () => {
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expect(formatNumber("1000" as any)).toBe("0");
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expect(formatNumber(null as any)).toBe("0");
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expect(formatNumber(undefined as any)).toBe("0");
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expect(formatNumber({} as any)).toBe("0");
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expect(formatNumber([] as any)).toBe("0");
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});
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});
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describe("real-world examples", () => {
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it("should format social media counts correctly", () => {
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expect(formatNumber(1234)).toBe("1.2k"); // 1.2k followers
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expect(formatNumber(45678)).toBe("45.7k"); // 45.7k likes
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expect(formatNumber(1234567)).toBe("1.2m"); // 1.2m views
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expect(formatNumber(9876543210)).toBe("9.9b"); // 9.9b population
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});
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it("should format file sizes", () => {
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expect(formatNumber(1024, 0)).toBe("1k");
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expect(formatNumber(1536, 1)).toBe("1.5k");
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expect(formatNumber(1048576, 0)).toBe("1m");
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});
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});
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});
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‎src/formatNumber.ts‎

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export function formatNumber(num: number, digits = 1): string {
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if (typeof num !== 'number' || isNaN(num)) return '0';
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const units = [
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{ value: 1e9, symbol: 'b' },
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{ value: 1e6, symbol: 'm' },
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{ value: 1e3, symbol: 'k' },
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{ value: 1, symbol: '' },
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];
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const isNegative = num < 0;
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const absNum = Math.abs(num);
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const unit = units.find(u => absNum >= u.value) || units[units.length - 1];
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const formatted = (absNum / unit.value).toFixed(digits);
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const clean = formatted.replace(/\.0+$|(\.[0-9]*[1-9])0+$/, '$1');
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return `${isNegative ? '-' : ''}${clean}${unit.symbol}`;
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}

‎src/index.ts‎

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export { isValidEmail } from "./isValidEmail";
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export { isValidGoogleMapsUrl } from "./isValidGoogleMapsUrl";
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export { isValidHttpUrl } from "./isValidHttpUrl";
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export { formatNumber } from "./formatNumber";
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export { shuffleArray } from "./shuffleArray";
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export { toKebabCase } from "./toKebabCase";
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export { unslugify } from "./unslugify";

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