data.table := assignments when variable has same name as a column

Question

I found this strange behavior when assigning a value to a position. If the variable has the same name as a column it thinks we are talking about the column:

Answer 1

You can always use get, which allows you to specify the environment:

dt1[1, a := get("a", envir = .GlobalEnv)]
#    a
#1: 18

Or just:

a <- 42
dt1[1, a := .GlobalEnv$a]
#    a
#1: 42