Problem Statement

In programming, a gotcha is a valid construct in a system, program or programming language that works as documented but is counter-intuitive and almost invites mistakes because it is both easy to invoke and unexpected or unreasonable in its outcome. Give an example or examples of common gotchas in your programming language and what, if anything, can be done to defend against it or them without using special tools.

Let's start with the solution:

say 123 ~ 456; # join two integers together
say "12" + "5.7"; # add two numeric strings together
say .sqrt for <4 6 8>; # take the square root of several allomorphic numerics


say my $bag = .Bag;
say $bag{'a'}; # a count?
say $bag< a >; # another way


say my $bag = (1, '1', '1', <1 1 1>).Bag;
say $bag{ 1 }; # how many 1s?
say $bag{'1'}; # wait, how many?
say $bag< 1 >; # WAT
dd $bag; # The different numeric types LOOK the same, but are different types behind the scenes


.say for (1,2,3), (4,5,6);


.say for (1,2,3);


.say for (1,2,3),;


.say for flat (1,2,3), (4,5,6);