click site Subscripting in R
Web Site [ gives the same data type as the data it is applied to.
[[ and $ extract the element and the data type is not necessarily the same as that of the data it is applied to.
queres namorar comigo no inglês $ does partial matching.
[ and [[ don’t.
site de rencontre veufs veuves $ does not evaluate.
[ and [[ evaluate their arguments.