javascript – `void` function to replace if-else with a short-circuit expression

This is the "code in question" in the following code:

const s = "waterrfetawx";
const del = 2;
palindromePossible function (str, deleteAtMost) {
const set = new Set ();
for (let i = 0, len = str.length; i <len; i ++) {
const char = str[i];
void (set.delete (char) || set.add (char)); // <- code in question
return set.size <= deleteAtMost + 1;

The code in question can also be written like this:

if (set.has (char)) {
set.delete (char)
} other {
set.add (char)

I'm not too sure if empty(...) is considered "clean", that is, readable, maintainable, and clear because it encapsulates only one expression in an instruction. How would you have written better?