Counting a character in items

Question

I have this function :

function MaFonction10()
     let myList1 = ["self-made-man", "rendez-vous", "forget-me-not"]
     for elem in myList1
        echo len(elem)
     endfor
endfunction

I vould like to get the number of hyphens or letter "a"s (for example) in each item, instead of the total number of letters.

Answer 1

You can use split() on a string, with a pattern of \zs, to split it into a list of characters.

Then you can use filter() on that list to only keep the matching character.

Finally, you can take the len() of the resulting list.

For example, to count the number of dashes in "elem":

echo len(filter(split(elem, '\zs'), {_, val -> val ==# "-"}))

UPDATE:

As suggested by @D.BenKnoble, using the more modern method syntax makes this nicer:

echo elem->split('\zs')->filter({_, val -> val ==# "-"})->len()

As noticed by @ArseneAsedrith, we don't need to go through all this trouble with splitting and filtering, since the count() function takes care of this exact case:

echo count(elem, "-")

Or:

echo elem->count("-")

Answer 2

Thank you. I have an other solution too :

function! MyFunction()
let myPonct = ["-"]
let myList = ["self-made-man", "rendez-vous", "forget-me-not"]
For elem in myPonct
        for elem2 in myList
            echo count(elem2,elem) 
        endfor
Endfor
endfunction