String text length (counting characters include space)
字串長度 (算出字元長度)
Description:
Len(X): to count the total length of a string X
example: often be used at submit required
a length of characters limitation
usage: often combines with Trim(X), Right(X,n), Left(X,n), Min(X,m,n)
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do not use length(________)
do not use len("_______")