group-by

Group an array of values by property or callback function.

Installation

$ component install component/group-by
$ npm install group-by

API

groupBy(array, prop)

Map returning a new array:

var groupBy = require('group-by');

var log1 = { type: 'log', version: '1.0.0' };
var log2 = { type: 'log', version: '1.1.0' };
var log3 = { type: 'log', version: '1.3.0' };
var app1 = { type: 'app', version: '1.0.0' };
var app2 = { type: 'app', version: '1.1.0' };

var nodes = [log1, app1, log2, log3, app2];

groupBy(nodes, 'type');

yields:

{ log: 
   [ { type: 'log', version: '1.0.0' },
     { type: 'log', version: '1.1.0' },
     { type: 'log', version: '1.3.0' } ],
  app: 
   [ { type: 'app', version: '1.0.0' },
     { type: 'app', version: '1.1.0' } ] }

groupBy(array, fn)

Group with an arbitrary fn, returning a key name:

groupBy(users, function(user){
  return user.pets.length
    ? 'hasPets'
    : 'noPets';
})

License

MIT