openlayers/ol3 — pull request #1037 by fredj (2013-09-18 15:27:35+00:00)
Title: ol.TileCoord.getKeyZXY optimization 

Optimize the `ol.TileCoord.getKeyZXY` function by removing the local array creation and by using string concatenation instead of array.join.

See http://jsperf.com/array-join-string-concat/2 for a comparaison between array join and string concat.