Swap key with value JSON

Question

I have an extremely large JSON object structured like this:

{A : 1, B : 2, C : 3, D : 4}

I need a function that can swap the values with

Answer 1

With pure Ramda in a pure and point-free style:

const swapKeysAndValues = R.pipe(
   R.toPairs,
   R.map(R.reverse),
   R.fromPairs,
);

Or, with a little more convoluted ES6 version, still pure functional:

const swapKeysAndValues2 = obj => Object
    .entries(obj)
    .reduce((newObj, [key, value]) => ({...newObj, [value]: key}), {})