unary operators

Syntax

not <operand>
- <operand>

not true
not false
not bookIsHardcover()

-numericVariable
-5
- myDebt()

Explanation

not

The not operator reverses a boolean. So if operand evaluates to true, not gives you false, if operand evaluates to false, not turns it into true.

negation

The - operator flips the sign on a number. E.g. if you use it with the number 5, or a variable containing that number, it will turn it into -5. If you use it with e.g. -66, it will turn it into 66.