Power Automate expressions operate on typed values. The number 2 and the text '2' can look identical on a card, but a strict equals comparison treats them differently. Boolean true also differs from the text 'true'. Convert source text when the business rule requires a number; don't solve a type mismatch by changing the rule to a different question.
length counts elements of an array or characters of text. A two-row array and the string that prints those rows are different inputs. if chooses one value after evaluating its Boolean condition. The exercises include zero, an empty array and a numeric-looking reference. Those cases help you decide whether a field is a quantity to calculate or an identifier to preserve. Use Run history to inspect the returned value's type as well as its appearance.