I read many posts on SO about the difference between short and long form for logicals operators, but I need an explicit precision.
I read that :
The longer form evaluates left to right examining only the first element of each vector.
Then, is this :
c(TRUE, TRUE) && c(TRUE, NA)
strictly the same operation than this :
(c(TRUE, TRUE) & c(TRUE, NA))[1]
The result of the logical & between the 1st element of the 1st vector and the 1st element of the second vecor ?
If this is right, what is the interest of returning simply the value returned by the logical operator between the first element of each vector ?
I supposed it shouldn't be used with vectors then ?
?'&&' gives the place that you want the longer form:
The longer form is appropriate for programming control-flow and typically
preferred in if clauses.
if takes a single value. Unfortunately, && doesn't give a warning if a vector exceeds length 1 (if does give a warning) so it's harder to catch such a mistake.
Indeed, you shouldn't be using && with vectors of length other than 1.