There's also an alternative notation that's common:
FILES=`find . name "*.pdf"`
Note that the delimiter for the command string is the "backtick" character, sometimes known as "left apostrophe". It's not the same thing as the normal (right) aprostrophe. On many keyboards, it's located to the left of the "1" key. In my case, it's on the same key as "~".
An IDE is no substitute for an Intelligent Developer.