Let's say you need to find out how many characters, like e.g. a, or b, or w, or any other alphabetic character, or even digits, are there in a text string subject to your analysis.
Here is an example of a string located in cell A2:
Security guards at the hotel make sure guests remain in isolation, while police outside ensure no one enters the premises.
I want to count all characters (i.e. determine their frequency), from a to z (and A to Z) present within that string. This snip shows how easily it can be done using the ARRAY formula presented here: