constantCase()

constantCase(str): string

Converts a string to CONSTANT_CASE.

note

Handles camelCase, kebab-case, space-separated strings, and acronyms.

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Parameters

str: string

The string to convert.

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Returns: string

The string in CONSTANT_CASE.

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Since

2.0.0

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Performance

O(n) where n is string length. Multiple regex passes.

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Also known as

constantCase (es-toolkit) · ❌ (Lodash, Remeda, Radashi, Ramda, Effect, Modern Dash, Antfu)

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Example

constantCase('helloWorld');       // => 'HELLO_WORLD'
constantCase('background-color'); // => 'BACKGROUND_COLOR'
constantCase('foo bar');          // => 'FOO_BAR'
constantCase('parseHTMLString');  // => 'PARSE_HTML_STRING'
constantCase('--foo--bar--');     // => 'FOO_BAR'

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How it works?

Converts a string to CONSTANT_CASE format. All uppercase, words separated by underscores.

Conversion Examples

Input	Output
helloWorld	HELLO_WORLD
background-color	BACKGROUND_COLOR
foo bar	FOO_BAR
parseHTMLString	PARSE_HTML_STRING

Use Case: Environment Variables

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Use Cases

Generate constants 📌

Convert strings to CONSTANT_CASE for environment variables or Redux action types. Critical for code generation tools.

#generate#constants#environment#variables#Redux#actions#design system

const envVar = constantCase('api url'); // 'API_URL'
const action = constantCase('fetch users'); // 'FETCH_USERS'

Create enum keys

Generate standardized enum member names from display text.

#create#enum#keys#members#standardize#generation

const enumKey = constantCase('Pending Approval'); // 'PENDING_APPROVAL'