The star made the announcement while promoting the third season of the Batman prequel drama on "The Late Show with Seth Meyers", reported Contactmusic.
"It was a little bit odd. What was interesting was sort of how much I didn't know that I knew until I actually got there.
"It was like, 'Oh, I know the answer to that question', because I've sat here for three years from a different perspective. Everybody has to say 'yes' to you. It was really really fun, I really enjoyed it. We have an amazing cast, so being able to work with them in that way was really fun."