Recently presumably from an update when using data.table in an R Notebook (RStudio), data.tables have been prinitng themselves to the console when I use the walrus operator to modify or create a column in place, e.g,
dt[, newcol := oldcol + 5]
This now prints the resulting data.table out in the console, when this used to not happen. I'm aware that I could use
dt <- dt[, newcol := oldcol + 5]
or invisible() to silence this, but my problem is, I maintain a big library of R Notebooks that all have nice, pretty output, I'd like to not have to change every single line that uses this.
Is this an update to data.table, and is there a global way to silence these messages? Can I hope it goes away in a future version?
I'm using R 4.5.3, data.table 1.18.2.1 and RStudio 2026.01.1 Build 403
UPDATE: Tested on R 4.6.0, data.table 1.18.2.1 and RStudio 2026.04.0 Build 246 still saw the same behavior.
Console output from running in a code chunk in an .Rmd file:
> library(data.table)
> dt <- data.table()
> dt[, a := 1]
a
<num>
1: 1
>
And below the code chunk:
Typing directly into the console:
> dt[, b := 2]
>
No console output is seen.