Former Perl language contributor here. A sibling comment to this already pointed out that you must use strict mode with Perl to retain your well being. The two

Former Perl language contributor here. A sibling comment to this already pointed out that you must use strict mode with Perl to retain your well being. The two languages certainly both have their terrible warts. I think in the implicit conversion gotchas, JS is actually markedly worse. Perl has polymorphic values, but somewhat typed (for its basic types) operators (eg "eq" for strings, "==" for integers). JS has both implicit value type conversions and overloaded operators. That leads to an unholy level of indeterministic mess.