In the following code:

const names = 'Harry Trump  ;Fred Barney; Helen Rigby ;  ;   ; Bill Abel ;Chris Hand '
let re = /\s*(?:;|$)\s*/;
console.log(names.split(re));
console.log(names.split(re).filter((e) => {return e}));

The second log statement filters out the empty strings. Why is that so, as I would expect a filter that 'returns itself' to basically do nothing, but it seems to evaluate the truthiness of the expression.