sprintf(): number of decimal places as an argument

Question

Current solution is

dp <- 2
sprintf(paste0("%.", dp, "f"), 0.123)

Hoped-for solution has no paste0() and is similar to

sprintf("%.{%2$d}f", 0.123, 2L)

Except that it works.

Answer 1

You can use a * to insert dp into the format.

dp <- 2
sprintf("%.*f", dp, 0.123)
# [1] "0.12"

Answer 2

Some other possibilities:

# option 1
prettyNum(0.123, digits = dp)

# option 2
formatC(0.123, digits = dp, format = 'f')