hey have change in lot of places camelcase snail_case.

i have following example:

billingaddress paymentdetails

i tried use find , replace regex in phpstorm

in 'find' input field put in:

([a-z])

in 'replace' input field put in:

_\l$1

result got:

billing_laddress payment_ldetails

what need change in order following result:

billing_address payment_details

first open find , replace functionality ctrl + r , check boxes match case , regex (and if necessary in selection):

1. replace camelcase snail_case in in question:

find: ([a-z])
replace: _\l$1

something -> some_thing

2. replace uppercase words lowercase words use \l

find: (\w*)
replace: \l$1

something -> something

3. replace lowercase words uppercase words use \u

find: (\w*)
replace: \u$1

something -> something

4. replace first character of words lowercase use \l

find: (\w*)
replace: \l$1

something -> something

5. replace first character of words uppercase use \u

find: (\w*)
replace: \u$1

something -> something

note: add boundaries

you best results adding additional boundaries suit specific case, example single ' or double quotes " or line breaks \n

regex documentation

check details on additional regular expression syntax documentation phpstorm or webstorm.