Vielzeug

Appearance

constant ​

Problem ​

You need a function that always returns the same value — for example as a default callback, a stub, or a placeholder in a composition pipeline.

Solution ​

Use constant(value) to return a zero-argument function that always returns value.

ts
import { constant } from '@vielzeug/arsenal';

const alwaysTrue = constant(true);
alwaysTrue(); // true
alwaysTrue(); // true

[1, 2, 3].map(constant('x')); // ['x', 'x', 'x']

Pitfalls ​

  • The value is captured by reference for objects — all calls return the same object instance.