syntax unless
Documentation for syntax unless
assembled from the following types:
language documentation Control flow
From Control flow
(Control flow) control flow unless unless
When you get sick of typing "if not (X)" you may use unless
to invert the sense of a conditional statement. You cannot use else
or elsif
with unless
because that ends up getting confusing. Other than those two differences unless
works the same as if:
unless 1 ; # does not say anything, since 1 is true
unless 1 "1 is false".say ; # syntax error, missing block
unless 0 ; # says "0 is false"
unless 42.say and 1 ; # says "42" but does not say "43"43.say unless 42.say and 0; # says "42" and then says "43"43.say unless 42.say and 1; # says "42" but does not say "43"= 1; unless 0 ; # says "1"= 1; unless 0 -> ; # says "0"= 1; unless False -> ; # says "False"my = 0; say (1, (unless 0 ), 3, ); # says "(1 2 3 42)"my = 0; say (1, (unless 1 ), 3, ); # says "(1 3 0)"