jquery/jquery — pull request #905 by mekwall (2012-08-23 13:17:36+00:00)
Title: String concatenation instead of join

Since `slice` only takes two arguments it's better to specify these two and build the name for `pushStack` by string concatenation instead of the slower `join` on the `arguments` object.

This change results in both less code and a performance boost of `slice` with up to ~50% (tested in latest Firefox and Chrome).

Check [this JSPerf](http://jsperf.com/wrapped-array-index-vs-eq/2)

Credits to [seutje](https://github.com/seutje) for the heads up!