How to recursively zip a folder and its subfolders and add password protetion+encryption

Below I am compressing all files and subfolders in the folder /home/oracle/outputfiles:

cd /home/oracle/outputfiles
zip -r --encrypt myzipfile.zip *

You will be prompted for a password, which has to be verified.
If you are located in the parent directory, use

zip -r -q myzipfile mydir

where myzipfile is the name of the resulting zip file, and mydir is the name of the directory.
The .zip extension will be added to myzipfile automatically.