camelcase

Convert a dash/dot/underscore/space separated string to camelCase or PascalCase: foo-bar → fooBar

Correctly handles Unicode strings.

If you use this on untrusted user input, don't forget to limit the length to something reasonable.

Install

npm install camelcase

Usage

import camelCase from 'camelcase';
camelCase('foo-bar');
//=> 'fooBar'
camelCase('foo_bar');
//=> 'fooBar'
camelCase('Foo-Bar');
//=> 'fooBar'
camelCase('розовый_пушистый_единорог');
//=> 'розовыйПушистыйЕдинорог'
camelCase('foo bar');
//=> 'fooBar'
console.log(process.argv[3]);
//=> '--foo-bar'
camelCase(process.argv[3]);
//=> 'fooBar'
camelCase(['foo', 'bar']);
//=> 'fooBar'
camelCase(['__foo__', '--bar']);
//=> '__fooBar'

[!NOTE]

Not idempotent in general. camelCase('{ A') → '{A', but camelCase('{A') → '{a'.

> Mixed case input is not idempotent either, because the word boundaries have to be guessed: camelCase('Ac_c A') → 'acCA', but camelCase('acCA') → 'acCa'.

API

camelCase(input, options?)

input

Type: string | readonly string[]

The string to convert to camel case.

options

Type: object

##### pascalCase

Type: boolean\ Default: false

Uppercase the first character: foo-bar → FooBar

import camelCase from 'camelcase';
camelCase('foo-bar', {pascalCase: true});
//=> 'FooBar'
camelCase('foo-bar', {pascalCase: false});
//=> 'fooBar'

##### preserveConsecutiveUppercase

Type: boolean\ Default: false

Preserve consecutive uppercase characters: foo-BAR → fooBAR

import camelCase from 'camelcase';
camelCase('foo-BAR', {preserveConsecutiveUppercase: true});
//=> 'fooBAR'
camelCase('foo-BAR', {preserveConsecutiveUppercase: false});
//=> 'fooBar'

##### capitalizeAfterNumber

Type: boolean\ Default: true

Controls whether letters immediately following digits are treated as word boundaries.

When true (default): Capitalize the first letter immediately following a numeric sequence, unless that letter is itself immediately followed by a separator. This is similar to Lodash, which also capitalizes after a number, but without the separator condition.

The extra condition keeps a token like b2b intact, so b2b_registration becomes b2bRegistration rather than b2BRegistration. It also means a trailing separator can stop the capitalization, as in 1a → 1A but 1a. → 1a.

When false: Do not treat digits as word boundaries. Preserve the original case of letters immediately following digits. Separators still create word boundaries. This follows the Google Java Style Guide which treats numbers as non-boundary characters.

import camelCase from 'camelcase';
camelCase('foo2bar', {capitalizeAfterNumber: true});
//=> 'foo2Bar'  (capitalizes 'b' after digit)
camelCase('foo2bar', {capitalizeAfterNumber: false});
//=> 'foo2bar'  (preserves lowercase 'b')
// Preserves original case after numbers when false
camelCase('Textures_3d', {capitalizeAfterNumber: false});
//=> 'textures3d'  (preserves lowercase 'd')
camelCase('Textures_3D', {capitalizeAfterNumber: false});
//=> 'textures3D'  (preserves uppercase 'D')
// Separators still create boundaries
camelCase('foo_2_bar', {capitalizeAfterNumber: false});
//=> 'foo2Bar'  ('bar' follows separator, not digit)

##### locale

Type: false | string | readonly string[]\ Default: The host environment’s current locale.

The locale parameter indicates the locale to be used to convert to upper/lower case according to any locale-specific case mappings. If multiple locales are given in an array, the best available locale is used.

import camelCase from 'camelcase';
camelCase('lorem-ipsum', {locale: 'en-US'});
//=> 'loremIpsum'
camelCase('lorem-ipsum', {locale: 'tr-TR'});
//=> 'loremİpsum'
camelCase('lorem-ipsum', {locale: ['en-US', 'en-GB']});
//=> 'loremIpsum'
camelCase('lorem-ipsum', {locale: ['tr', 'TR', 'tr-TR']});
//=> 'loremİpsum'

Setting locale: false ignores the platform locale and uses the Unicode Default Case Conversion algorithm:

import camelCase from 'camelcase';
// On a platform with tr-TR.
camelCase('lorem-ipsum');
//=> 'loremİpsum'
camelCase('lorem-ipsum', {locale: false});
//=> 'loremIpsum'

Related

• decamelize - The inverse of this module
• titleize - Capitalize every word in string
• humanize-string - Convert a camelized/dasherized/underscored string into a humanized one
• camelcase-keys - Convert object keys to camel case