groupBy vs.indexBy

groupby-vs-indexby.md

	.groupBy	.indexBy
return type	object	object
each key:value, value type is	array (contains values from original list)	value from original list
if value has same key	group	override; keep last value

Example: .indexBy

var stooges = [{name: 'moe', age: 40}, {name: 'larry', age: 50}, {name: 'curly', age: 50}];
_.indexBy(stooges, 'age');
=> {
  "40": {name: 'moe', age: 40},
  "50": {name: 'curly', age: 50}
}