Why does regex work like this?

Question

Node.js

var symbol = "s cchh'shchcz'' ";

console.log(symbol.split(/(sh|sch|ch|cz|yu|ya|yo|zh|''|'|.)/))

[
  '', 's',  '', ' ',  '', 'c',
  '', 'ch', '', 'h',  '', "'",
  '', 'sh', '', 'ch', '', 'cz',
  '', "''", '', ' ',  ''
]

Puts empty values ​​in the array after one character, why is that?

Answer 1

Because you wrote it like this =)

/(sh|sch|ch|cz|yu|ya|yo|zh|''|'|.)/
                                ^
                             // └ Сопоставляется с любым символом

This is how it works correctly
/(sh|sch|ch|cz|yu|ya|yo|zh|''|')/