Conditional Fields beyond show and hide

Instead of doling out a lot of Jquery or JS, can it be done where a field can be populated with a particular value if a condition is met?  I see this feature in the WPDATATABLES where if a cell is xyz, then you can change the color or even the content besides showing or hiding.

If I have a particular entry on a drop-down field, before the submission, I want that value copied over to a memo field which is a text area.