Extracting hashtags out of a string.

Do you care about Unicode or non-English hashtags?

"Mmmm #yummy #donut at #CZ #中文 #.dou #。#？#♥️ #にほ".match(/#[\p{L}]+/ugi)
=> (5) ["#yummy", "#donut", "#CZ", "#中文", "#にほ"]

As explained by this answer: https://stackoverflow.com/a/35112226/515585

\p{L} matches unicode characters

u the PCRE_UTF8 modifier, this modifier turns on additional functionality of PCRE that is incompatible with Perl.

Just use a regular expression to find occurences of a hash followed by non-whitespace characters.

"Mmmm #yummy #donut at #CZ".match(/#\w+/g)
// evaluates to ["#yummy", "#donut", "#CZ"]

This will do it for anything with alphabetic characters, you can extend the regexp for other characters if you want:

myString.match(/#[a-z]+/gi);