Strings / len

len(value)

Returns the length of the argument, which may be a string or a dataset. If the argument is a string, it returns the number of characters in the string. If the argument is a dataset, it returns the number of rows in the dataset. Will return zero if the argument is null.

len("Hello World")

... returns 11

len({Root Container.Table.data})

... returns the number of rows in the table.