String length in stored procedure, how?

Variable v_len is declared as INT

I would have hoped something like the following to work:

v_len  = length("Hello");

v_len  = len("Hello");

v_len  = strlen("Hello");

and I cant find anything refering to the determination of the length of strings except strlen with CE_CALC, but I cannot figure out how to use it for a case involving determining the length of the content of a fixed string (or a scalar variable).