Captures can be available outside of regular expressions.
This is found in programming languages, code editors.
Backreferences can be used in find-and-replace operations.
An example is “I love hot coffee.”
Find: /(love) hot/
Replace: *\1*
Use a backreference to find the first capture.
Another example is a list of names like so:
Stephen King
Margaret Atwood
Douglas Adams
We have the above list and we want to reverse each one, so that the format is: last name, first name.
Find: /^(.+) (.+)$/ Replace: \2, \1
Then it shows the following:
King, Stephen
Atwood, Margaret
Adams, Douglas
Can create regular expression.
Test against sample data.
Add capturing groups
Write replacement strings using backreferences (\1 or $1)
Include anything not captured that should be retained.
/^.+ .+$/
Simple wildcard repeat regex that matches all of the above names.
/^(.+) (.+)$/
Same, but captured within parenthesis.
Can then press the Replace but in regexr and to get the above result, can do \2, \1. It then displays the results as:
King, Stephen
Atwood, Margaret
Adams, Douglas
To match either one of the following:
self-reliance
reliance
We can do alternation to match both of them.
We can do /(self-)?reliance/ or /((self-)?reliance)/
When replacing, you can put asterixs around it like so *\1* which adds asterisks around the search terms.
Can replace with HTML, for example <strong>$1</strong> ($1 or \1 depending on the regex editor you use).