Boolean

Booleans are very primitive, they can only be 'true' or 'false'.

Comparisons

Aside from equality == and inequality !=, booleans also accept the following operators:

& logical AND

true  & true  == true
true  & false == false
false & true  == false
false & false == false

AND short-circuits expression if left-hand side is false

| logical OR

true  | true  == true
true  | false == true
false | true  == true
false | false == false

OR short-circuits expression if left-hand side is true

% logical XOR (exclusive OR)

true  % true  == false
true  % false == true
false % true  == true
false % false == false

XOR always evaluates both sides of the expression

Bang operator

!! coerces any type into boolean, like so:

• null -> false
• zero (number) -> false
• non-zero (number) -> true
• empty (text/list/scope/chunk) -> false
• non-empty (text/list/scope/chunk) -> true
• method -> true
• error -> false

logical AND/OR (&, |) and conditional flows (=>, ?) will implicitly coerce to boolean

See also

• Boolean prototype extensions
• Flow control