Javascript swap function to swap map data

Following is the swap function in Javascript to change a map from k -> v to v -> k. If the data has duplicate values you will loose them.

function swap(json) {
    var res = {};
    for (var key in json) {
        res[json[key]] = key;
    }
    return res;
}

Following is a full example with data to demonstrate the swap functionality

function swap(json) {
    var res = {};
    for (var key in json) {
        res[json[key]] = key;
    }
    return res;
}

let data = {
  "a": '1',
  "b": '2',
  "c": '3',
}

console.log(swap(data));

Output

{ '1': 'a', '2': 'b', '3': 'c' }

You can try this code online here https://onecompiler.com/javascript/3vy54pdge