Arrayformula to get the max number of consecutive occurrence of a character inside a string

Question

I have strings of different length like the one below:

LWLLLLXWLWWWXWWWXWWLWLWLWWWWLWLLLXXWLLLLL

From this string, I'd like to extract the maximum number of consecutive occurrence of L. Here it would return 5 because the max is the one in bold.

I was able to come with a formula I have to put on every row (where A2 is the string and B2 is the character, L in the example):

=IFERROR(ARRAYFORMULA(MAX(LEN(IFNA(REGEXEXTRACT(A2,B2&"{"&SEQUENCE(LEN(A2)-LEN(SUBSTITUTE(A2,B2,)),1,LEN(A2)-LEN(SUBSTITUTE(A2,B2,)),-1)&"}"),)))),)

But I am looking for a unique =ArrayFormula() formula to avoid replicating this formula on every rows.

You'll find an example to play with following the link below:

https://docs.google.com/spreadsheets/d/1OZ6HAx0Z317fRyjjEVYphZNrlXdwc7s3z7vMc05HdoI/edit?usp=sharing

Answer 1

Use split(A2:A, "XW", true) and query(), like this:

=arrayformula( 
  transpose( 
    query( 
      transpose( len( split(A2:A, "XW", true) ) ), 
      "select " & join( ", ", "max(Col" & sequence(rows(A2:A)) & ")" ) & 
      "label " & join( ", ", "max(Col" & sequence(rows(A2:A)) & ") ''" ), 
      0 
    ) 
  ) 
)