underscore

Converts a string to snake_case.

underscore

Signature

function underscore(str: string): string

Parameters

• str - The string to convert

Returns

String in snake_case format.

Examples

import { underscore } from 'strio'

// From camelCase
underscore('helloWorld')
// "hello_world"

// From PascalCase
underscore('HelloWorld')
// "hello_world"

// From kebab-case
underscore('hello-world')
// "hello_world"

// From spaces
underscore('hello world')
// "hello_world"

// With numbers
underscore('userProfile2')
// "user_profile2"

// Multiple separators
underscore('hello---world  test')
// "hello_world_test"

// Already snake_case
underscore('hello_world')
// "hello_world"

Use Cases

Database Column Names

import { underscore } from 'strio'

function toColumnName(fieldName: string): string {
  return underscore(fieldName)
}

toColumnName('firstName')
// "first_name"

toColumnName('createdAt')
// "created_at"

Environment Variables

import { underscore } from 'strio'

function toEnvVar(name: string): string {
  return underscore(name).toUpperCase()
}

toEnvVar('apiKey')
// "API_KEY"

toEnvVar('databaseUrl')
// "DATABASE_URL"

File System Naming

import { underscore } from 'strio'

function createSnakeFileName(name: string): string {
  return underscore(name) + '.py'
}

createSnakeFileName('UserProfile')
// "user_profile.py"

createSnakeFileName('apiClient')
// "api_client.py"

Related Functions

• camelize - Convert to camelCase
• pascalize - Convert to PascalCase
• dasherize - Convert to kebab-case

See Also

• String Manipulation Guide
• API Reference