Regex replace uppercase with lowercase letters in PhpStorm/Webstorm (Intellij-IDEA)
First open Find and Replace functionality with CTRL + R and then check the boxes Match Case and Regex (and if necessary In Selection):
1. To replace camelCase to snail_case as in in the question:
find: ([A-Z])
replace: _\l$1
someThing -> some_thing
2. To replace UPPERCASE words to lowercase words use \L
find: (\w*)
replace: \L$1
SOMETHING -> something
3. To replace lowercase words to UPPERCASE words use \U
find: (\w*)
replace: \U$1
something -> SOMETHING
4. To replace first character of words with lowercase use \l
find: (\w*)
replace: \l$1
Something -> something
5. To replace first character of words with UPPERCASE use \u
find: (\w*)
replace: \u$1
something -> Something
Note: Add some extra boundaries
You get best results by adding some additional boundaries that suit your specific case, for example single ' or double quotes " or line breaks \n
Regex Documentation
Check for details on additional Regular Expression Syntax the documentation for PHPStorm or WebStorm.
According to the PHPstorm docs and according to my test, this works now:
_\l$1
What do I need to change in order to get following result:
Nothing/Everything. It's simply not supported ATM.
https://youtrack.jetbrains.com/issue/IDEA-70451 -- watch this ticket (star/vote/comment) to get notified on progress.
UPDATE: This functionality is now implemented and available since PhpStorm v10.