How to count the number of characters in a string

I'm working in a program with a single string user input but I need to know the number of characters in the string so I can handle the array and I don't know how to count them. I tried to solve this using an array itself but the problem is kinda redundant...

LEN(STRING$) will give you the length of the string.

LEN(STRING$) will give you the length of the string.

Thank you very much, man.