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Capitalize a string

Written byPhuoc Nguyen
Created
11 Apr, 2023
Last updated
19 Apr, 2020
Category
String
Contributors
e
fahimfaisaal
JavaScript version
capitalize.js
const capitalize = (str) => `${str.charAt(0).toUpperCase()}${str.slice(1)}`;

// Or
const capitalize = ([first, ...rest]) => `${first.toUpperCase()}${rest.join('')}`;

// Or
const capitalize = (str) => str.replace(/^([a-z])/, (first) => first.toUpperCase());
TypeScript version
capitalize.ts
const capitalize = (str: string): string => `${str.charAt(0).toUpperCase()}${str.slice(1)}`;

// Or
const capitalize = ([first, ...rest]: string): string => `${first.toUpperCase()}${rest.join('')}`;

// Or
const capitalize = (str: string): string => str.replace(/^([a-z])/, (first) => first.toUpperCase());
Examples
examples.js
capitalize('hello world'); // 'Hello world'

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