Tag Archive for: flatten

Flattening arrays of objects

Starting from the previous example we are going to flatten arrays of objects with 3 method:

  • map with join
  • forEach with concat
  • forEach with push

We are trying to do it in a functional way, clearer and shorter. The more (nested) elements you have, the better the map option will be versus forEach with concat. If we are looking for the fastest option, a classical for with push will be the best one as JapanFever said and the worst a forEach with concat.

Just launch these basic test I made in jsPerf and try yourself:



The more (nested) elements you have, the more equal the forEach will be comparing with the classical for.

JavaScript engines performance are improving constantly and I hope to see a better way to flatten using map xD