Is there a functionality where you can copy code from inside a block code or inline code? I currently use Boostnote which does have that feature, but their newer version did away with that.

Nope, Joplin does not have this feature.
Hi,
Any chance that this feature could be implemented?
It would make life easier when copy-pasting big codeblocks.
An icon to copy or just an option in the right click context menu would suffice.
Thanks!
Thanks mate, I totally missed that.
You’re fine. It just popped up out of nowhere very recently and most people missed it. Ha
And you are not the only one requesting this!
It's great that we now have a plugin for code blocks, but we still need one for inline code.
There is Joplin Plugins - Click to copy but it requires a non stand delimiter ([[…]]) and does not work for standard inline code (backquotes).
What we need is a solution so that a single click on any inline code (single backquotes) copies its content to clipboard.
Big news, there is now a one click copy solution for inline code as well!
It was implemented in the very recent 1.3.3 version of https://joplinapp.org/plugins/plugin/com.joplin.click.to.copy/
Simply set delimiters as backquotes instead of default [[ and ]]. They now work correctly.
Kudos to @ntczkjfg
Relevant links:
nice, being able to use backticks for this is handy!
As an update to this: I just pushed version 1.4.0. You can still set the start and end tokens to backticks if you prefer - but now, in settings, there are options to directly make inline code spans click-to-copy without having to change your tokens.
For anyone who wants all inline code spans to be click-to-copy, I recommend this over changing the tokens - it preserves the functionality of the plugin for other applications and is also a little cleaner visually with the CSS.