It won't work in JS because arrays are compared by reference, so it would always fail to match (I think immutable data structures, at proposal stage 2, would provide one potential fix for this, otherwise need a workaround such as bitmasking the array before performing a match). It not working isn't simply that pattern matching isn't present in the language, per se.

'It doesn't work in one particular language that happens to lack pattern matching, therefore it cannot work without pattern matching.'

In particular, pattern matching generally entails destructuring, which you do not need in order to make that particular example work.

it works in ruby without pattern matching, thanks to ruby's switch statement design where `switch a: case b` invokes `b.match(a)`