async, await
http://whatsthepointy.blogspot.com/2013/11/javascript-does-not-have-pass-by.html
pass by reference
JS has only pass by value
default params need to be right of non default params
we should not use langauge keywords for defining a variable as the the actual feature of the keyword will be lost
mutable types
Does all functions should have return statement
_ underscore
List last item can have comma unlike json last item