Lodash

invertBy

Object
since 4.1.0

Arguments

  • Object The object to invert.
  • Function The iteratee invoked per element.

Returns

Object the new inverted object.

This method is like _.invert except that the inverted object is generated from the results of running each element of object thru iteratee. The corresponding inverted value of each inverted key is an array of keys responsible for generating the inverted value. The iteratee is invoked with one argument: (value).

Example of Lodash _.invertBy

var object = { 'a': 1, 'b': 2, 'c': 1 };

_.invertBy(object);
// => { '1': ['a', 'c'], '2': ['b'] }

_.invertBy(object, function(value) {
  return 'group' + value;
});
// => { 'group1': ['a', 'c'], 'group2': ['b'] }