Package Exports

reduce-by

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Readme

reduce-by

Turn an array of values into an object by using a function to determine the key an item belongs to and a function to determine how an item is grouped under that key. reduceBy is like groupBy, but more generic.

install

$ npm install reduce-by

example

const reduceBy = require('reduce-by')

// group items by concatenating and use first character as the key
reduceBy(
  (group, v) => group + v,
  () => '',
  v => v.slice(0, 1),
  [ 'foo', 'bar', 'baz' ]
)
// => { f: 'foo', b: 'barbaz' }

api

`reduceBy(groupReducer, getInitialGroupValue, getKey, array)`

groupReducer(group, value) function that takes the accumulated group value and a value to be grouped and returns the new accumulated group value
- group accumulated group value
- value value to be added to the group
- => group accumulated group value
getInitialGroupValue() function that returns the initial value for groups
- => initialGroupValue
getKey(value) function that takes value and returns the key that value belongs to
- => key the key the value should be grouped under
array: [] an array of items to be turned into an object
=> object