Javascript Object.assign Alternative . The mergeObject() method is used to copy the values of all enumerable own properties from one or more source objects to a target object. It will return the target object.

merge-object.js

function mergeObject(target) {
    for (var i = 1; i < arguments.length; i++) {
        var source = arguments[i];
        for (var key in source) {
            if (source.hasOwnProperty(key)) {
                target[key] = source[key];
            }
        }
    }
    return target;
}