What do %/% and %% mean?

Question

I've recently seen code like this:

library(dplyr)
mtcars %.% mutate(carb_10 =  carb %/% 10)

And this....

mtcars %.% mutate(carb_10 =  carb %% 10)

Can anyone explain what %/% and %% do in above code?

Answer 1

In R:

• %% is the modulo operator
• example: 5 %% 3 will be equal to 2 as it is the remainder obtained on the integral division of 5 by 3

In Python, you can do it by simply using: %

• 5 % 3

---

In R:

• %/% is the integer division operator
• example: 5 %/% 3 will be equal to 1 as it is the quotient obtained on the integer division of 5 by 3

In Python, you can do it by simply using: //

• 5 // 3

Answer 2

From the ?"%%" help page

%% indicates x mod y and %/% indicates integer division. It is guaranteed that x == (x %% y) + y * ( x %/% y ) (up to rounding error) unless y == 0 where the result of %% is NA_integer_ or NaN (depending on the typeof of the arguments).