JavaScript: Swap Object Key/Value 🚀

Here is a function that reverse the key/value of object.

That is, value become key, vice versa.

/* [
xah_swap_obj_key_val(xObj)
return a new object that has its key and value swapped.
If values are not unique, the previous is overwritten.
Only enumerable key and string key counts.
URL http://xahlee.info/js/js_reverse_obj_key_val.html Version: 2018-06-04 2023-10-11
] */
const xah_swap_obj_key_val = ((xObj) => {
  const xnew = {};
  Object.keys(xObj).forEach((x) => {
    xnew[xObj[x]] = x;
  });
  return xnew;
});

// ssss---------------------------------------------------
// test

const xx = { a: 1, b: 2 };

console.log(
  JSON.stringify(xah_swap_obj_key_val(xx)) ===
    '{"1":"a","2":"b"}',
);