Calculate added characters between 2 strings (even when others are removed)

Question

I have an initial string which will be changed and I want to know how many new characters were added (even when others are removed).

For exemple:

Initial string ==> "I love Programming so much"
Changed string ==> "I used to love programming"


Changes:


"used to " 8 chars added
" so much" 8 chars deleted

The result I want is the number of added chars which is 8.

Can anyone help me please?

Have you tried comparing the length of the string before and after adding/removing characters? — Marco Aurelio Fernandez Reyes, Sep 01 '21 at 13:52
Folks, that would give them the value `0`. They want `8` (the number added, even though 8 were also removed). — T.J. Crowder, Sep 01 '21 at 13:54
@MarcoAurelioFernandezReyes both strings have 26 chars so the result will be 0 which is wrong — Yassine Soltani, Sep 01 '21 at 13:55
You might want to fix the strings in the question, one has `P` the other has `p`. Which also brings us to: What about if a character is **changed**? Does that count as an addition? — T.J. Crowder, Sep 01 '21 at 13:56
"Diffing" text is a complicated area. There should be libraries you can find that would help you with this. — T.J. Crowder, Sep 01 '21 at 13:57

score 7 · Answer 1 · answered Sep 01 '21 at 13:57

7

The number of characters you have to change to get from one string to another is called the Levenshtein distance, sounds like that might be what you want. You can find some JS implementations here.

answered Sep 01 '21 at 13:57

Jotha

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Thank you so much @Jotha this what i was looking for! – Yassine Soltani Sep 01 '21 at 14:18
After testing this solution it appeared that it's not what I needed , but I feel like I'm getting closer to find the right solution – Yassine Soltani Sep 01 '21 at 15:43

Calculate added characters between 2 strings (even when others are removed)

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