Run results for: forEach vs for len vs for in vs for of fix
created based off of an archived jsperf benchmark: http://web.archive.org/web/20191008221700/https://jsperf.com/foreach-vs-for-loop-vs-for-in-vs-for-of-vs-babel-for-of
change var to let.
for of returns the value directly. So you don't get value from testData array.