Create strings of a wordlist using replace-regexp

Question

I have a word list with a lot of words that I want to convert into a json file. To do this I need to make them strings and add a comma in the end of all words. I figured it would be nice to use regular expression to do this and I know about replace-regexp. What I have tried to do this, beginning with the file:

This 
Is 
An 
Example

To match each word I use ^([A-Za-z]+)$. I have tried it in https://regex101.com/ and it seems to work the way as expected. But how do I actually use these matches to add a " in front and back of each word to make strings of them?

"This"
"Is"
"An"
"Example"

I can not find in the documentation how to actually use the matches to add more characters.

Edit: After reading https://www.emacswiki.org/emacs/RegularExpression and experimenting with regex101 I found that the words is group 1, so "\1", (added a comma just to complete the json structure) should work, but it does not

Edit2: Just a more clear example of one of the most promising tries: replace-regexp <RET> ^([A-Za-z]+)$ <RET> "\1",

Answer 1

(and ) are ordinary characters in Emacs RegExp, you need to escape them with a / to make them a group, thus you should try

M-x replace-regexp <RET> ^\([A-Za-z]+\)$ <RET> "\1", <RET>

You can also use

M-x replace-regexp <RET> ^[A-Za-z]+$ <RET> "\&", <RET>

where \& stands for the whole match.

Answer 2

You can just read the file in, split it into lines, and then encode directly to json like this:

(require 'json)

(with-temp-file "words.json"
  (insert (with-temp-buffer (insert-file-contents "words.txt")
                (json-encode
                 (split-string (buffer-string) "\n" t)))))

This gives me a json file with these contents.:

["This","Is","An","Example"]