JSFiddle - React, Tailwind, and code Playground

by Richard Ayotte

JavaScript

var currentArrayObjects = [
    {registration: 1}    
    , {registration: 2}    
    , {registration: 3}    
    , {registration: 4}    
    , {registration: 5}    
    , {registration: 6}    
];

var newDownloadedArray = [
    {registration: 4}    
    , {registration: 5}    
    , {registration: 6}    
    , {registration: 7}    
    , {registration: 8}    
    , {registration: 9}    
];

var newRegistrations = _.difference(
        _.pluck(newDownloadedArray, 'registration')
       , _.pluck(currentArrayObjects, 'registration')
);

console.log(newRegistrations);