Question regarding for shell scripting.

I tried to run a command which simply generates SSH key with out prompting password.
After several trails , got the below command to run the script :

ssh-keygen -t rsa -N "" -f id_rsa
-N "" tells it to use an empty passphrase (the same as two of the enters in an interactive script)
-f id_rsa tells it to store the key into id_rsa.

The whole thing runs without you needing to supply any enter keys.