Last Updated: 3/6/2026

Literal Patterns

Literals are primitive JavaScript values, like numbers, strings, booleans, bigints, symbols, null, undefined, or NaN.


import { match } from 'ts-pattern';
 
const input: unknown = 2;
 
const output = match(input)
  .with(2, () => 'number: two')
  .with(true, () => 'boolean: true')
  .with('hello', () => 'string: hello')
  .with(undefined, () => 'undefined')
  .with(null, () => 'null')
  .with(NaN, () => 'number: NaN')
  .with(20n, () => 'bigint: 20n')
  .otherwise(() => 'something else');
 
console.log(output);
// => 'number: two'