Minor change made to ordering of statements in code block in order to correspond with ordering of concepts in preceding sentence

[cgrilson7]

This caused me some confusion. The sentence leading up to the code block refers to the indexing operators [[ as "the former" and $ as "the latter".

But in the code block, the order in which these operators are demonstrated is reversed ($ is "the former" and [[ is "the latter").

[lionel-]

Thanks!