count

• count

Count the occurrences of values extracted via the optional getter parameter (or directly using the array elements themselves).

The getter is a field path of getByPath or a callback function, used to provide a label for frequency statistics.

Added in v0.0.1

Usage

import { count } from 'parsnip-kit'

count([1, 2, 2, 3, 3, 3]) // Map { 1 => 1, 2 => 2, 3 => 3 }

const users = [
  { id: 1, name: 'Alice' },
  { id: 2, name: 'Bob' },
  { id: 1, name: 'alice' }
]
count(users, 'id') // Map { 1 => 2, 2 => 1 }

count(users, (user) => user.name.toLowerCase()) // Map { 'alice' => 2, 'bob' => 1 }

API

Type Parameter

Arg	Type	Description
T		Type of input array

Arguments

Arg	Type	Optional	Default	Description
data	T[]	false	undefined	Input array
getter	string | ((item: T, index: number, arr: T[]) => any)	true	undefined	Provide an identifier to distinguish the elements

Returns

Type
Map<any, number>