This dist shows you how to merge endless json objects in JavaScript.

mergeJson.js

function merge(json) {
    var sources = [].slice.call(arguments, 1);
    sources.forEach(function (source) {
        for (var property in source) {
            json[property] = source[property];
        }
    });
    return json;
}
// merge(json1, json2, json3)