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Why doesn't R allow $ operator on atomic vectors?

The following will display the error "Error in v $ a: $ operator is not valid for atomic vectors" (at least in version R.1.1.1.1):

v <- c(a='a',b='b') v$a

Apparently, R had previously admitted this, which makes me curious why.

EDIT: As indicated below, v$a would return NULL in earlier versions. Changed “quite recently” to “earlier” since I based it on old internet forums and was fixed below.

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2 answers

I believe the reason is that using v$a vs. v[['a']] is considered less secure.

EDIT: More on this LINK .

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The third paragraph of the "Details" section ?"$" :

'$ is valid only for recursive objects and is considered only in the below on recursive objects. Its use on non-recursive objects was deprecated in R 2.5.0 and removed in R 2.7.0.

R-2.7.0 was released in April 2008. Four years are far from being “recent,” but perhaps for a while you had several versions?

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Source: https://habr.com/ru/post/911412/

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