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which-collection (1.0.2)

Published 2026-02-24 14:08:36 +00:00 by atheaadmin

Installation

Setup this registry in your project .npmrc file:

registry=

To install the package using npm, run the following command:

npm install which-collection@1.0.2

or add it to the package.json file:

"which-collection": "1.0.2"

For more information on the npm registry, see the documentation.

About this package

which-collection

Which kind of Collection (Map, Set, WeakMap, WeakSet) is this JavaScript value? Works cross-realm, without instanceof, and despite Symbol.toStringTag.

Example

var whichCollection = require('which-collection');
var assert = require('assert');

assert.equal(false, whichCollection(undefined));
assert.equal(false, whichCollection(null));
assert.equal(false, whichCollection(false));
assert.equal(false, whichCollection(true));
assert.equal(false, whichCollection([]));
assert.equal(false, whichCollection({}));
assert.equal(false, whichCollection(/a/g));
assert.equal(false, whichCollection(new RegExp('a', 'g')));
assert.equal(false, whichCollection(new Date()));
assert.equal(false, whichCollection(42));
assert.equal(false, whichCollection(NaN));
assert.equal(false, whichCollection(Infinity));
assert.equal(false, whichCollection(new Number(42)));
assert.equal(false, whichCollection(42n));
assert.equal(false, whichCollection(Object(42n)));
assert.equal(false, whichCollection('foo'));
assert.equal(false, whichCollection(Object('foo')));
assert.equal(false, whichCollection(function () {}));
assert.equal(false, whichCollection(function* () {}));
assert.equal(false, whichCollection(x => x * x));
assert.equal(false, whichCollection([]));

assert.equal('Map', whichCollection(new Map()));
assert.equal('Set', whichCollection(new Set()));
assert.equal('WeakMap', whichCollection(new WeakMap()));
assert.equal('WeakSet', whichCollection(new WeakSet()));

Tests

Simply clone the repo, npm install, and run npm test

Dependencies

Dependencies

ID	Version
is-map	^2.0.3
is-set	^2.0.3
is-weakmap	^2.0.2
is-weakset	^2.0.3

Development Dependencies

ID	Version
@arethetypeswrong/cli	^0.15.0
@ljharb/eslint-config	^21.1.0
@types/for-each	^0.3.3
@types/object-inspect	^1.8.4
@types/tape	^5.6.4
aud	^2.0.4
auto-changelog	^2.4.0
eslint	=8.8.0
for-each	^0.3.3
in-publish	^2.0.1
npmignore	^0.3.1
nyc	^10.3.2
object-inspect	^1.13.1
safe-publish-latest	^2.0.0
tape	^5.7.5
typescript	next

Keywords

map set weakmap weakset collection.es6 es2015

Details

npm

2026-02-24 14:08:36 +00:00

0

Jordan Harband

Project Site

MIT

latest

7.1 KiB

Assets (1)

which-collection-1.0.2.tgz 7.1 KiB

Versions (1) View all

1.0.2 2026-02-24