Project: syntax-tree/estree-util-is-identifier-name

Package: estree-util-is-identifier-name@2.0.1

  1. Dependents: 0
  2. Check if something can be an ecmascript (javascript) identifier name
  1. tree 44
  2. ast 36
  3. javascript 23
  4. ecmascript 10
  5. estree 9
  6. character 5
  7. identifier 2


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estree utility to check if something can be an identifier.


What is this?

This package is a utility that can be used to check if something can be an identifier name. For example, a, _, and a1 are fine, but 1 and - are not.

When should I use this?

You can use this utility when generating IDs from strings or parsing IDs.


This package is ESM only. In Node.js (version 12.20+, 14.14+, 16.0+, or 18.0+), install with npm:

npm install estree-util-is-identifier-name

In Deno with esm.sh:

import * as isIdentifierName from 'https://esm.sh/estree-util-is-identifier-name@2'

In browsers with esm.sh:

<script type="module">
  import * as isIdentifierName from 'https://esm.sh/estree-util-is-identifier-name@2?bundle'


import {name, start, cont} from 'estree-util-is-identifier-name'

name('$something69') // => true
name('69') // => false
name('var') // => true (this does not handle keywords)

start(48) // => false (character code for `0`)
cont(48) // => true (character code for `0`)


This package exports the identifiers name, start, and cont. There is no default export.


Checks if value (string) is a valid identifier name (boolean).


Checks if the given character code (number) can start an identifier (boolean).


Checks if the given character code (number) can continue an identifier (boolean).


This package is fully typed with TypeScript. It exports no additional types.


Projects maintained by the unified collective are compatible with all maintained versions of Node.js. As of now, that is Node.js 12.20+, 14.14+, 16.0+, and 18.0+. Our projects sometimes work with older versions, but this is not guaranteed.


See contributing.md in syntax-tree/.github for ways to get started. See support.md for ways to get help.

This project has a code of conduct. By interacting with this repository, organization, or community you agree to abide by its terms.


MIT © Titus Wormer