vhas

Checks whether a collection contains a value.

Installation

Requires Node.js 8.3.0 or above.

npm i vhas

API

The module exports a has() function that has one other function attached to it as a method: has.any().

has()

Parameters

1. Bindable: collection (Array, Iterator, Map, Object, Set, string, Typed Array, or WeakSet): The collection from which to retrieve a value.
2. valueToCheck (any): The value whose presence in the collection is in question.
3. Optional: Object argument:
   • arrays / maps / sets / weakSets (arrays of classes/strings): Arrays of classes and/or string names of classes that should be treated as equivalent to Array/Map/Set/WeakSet (respectively).
   • inObj (boolean): Whether or not to search inherited properties if collection is an Object (i.e. not another recognized type). Defaults to false.
   • loose (boolean): Whether or not to identify values loosely (as defined by looselyEquals). Defaults to false.
   • looselyEquals (function): A callback that accepts two values and returns true if they are to be considered equivalent or false otherwise. This argument is only used if loose is true. If omitted, the default behavior will, among other things, consider arrays/objects to be equal if they have the same entries.
   • reflectObj (boolean): Whether or not to use reflection to include non-enumerable Object property values. Only takes effect if collection is an Object (i.e. not another recognized type). Defaults to false.

Return Values

• Returns true if valueToCheck matches an element in the collection. The match can be strict or loose depending on the configured options.
• Otherwise, returns false.

Example

const has = require('vhas')

const emptyObj = {}
const collection = [emptyObj]

has(collection, {}, {loose: true}) // true

has.any()

Use this function if you want to check whether a collection contains any one of a set of values. The signature is the same as the main function except that the second parameter is called valuesToCheck and takes an iterable (such as an array or string).

Example

const has = require('vhas')

const vowels = 'aeiou'

has.any('test', vowels) // true
has.any('xyz', vowels) // false

Related

The “k” family of modules works on keyed/indexed collections.

• khas
• kget
• kedit
• kset
• kinc
• kdel

The “v” family of modules works on any collection of values.

• vget
• vsize
• vadd
• vdel