array push all code example

Example 1: what does results.push({}) nodejs mean

const mongoose = require('mongoose');
    var data = async function () {
         var array = [];
         const finalResults = await new Promise((resolve, reject) => {
            mongoose.connection.collection("organizations").find({}).toArray(function(err, result) {
              resolve(result);
           });
      });

     for(var i = 0; i < finalResults.length; i++)
     {
          var a = finalResults[i].name;
           array.push(a);
      }
        return array;
    };

    module.exports = {
        data: data,
    };

Example 2: js add array items to array

var arrayA = [1, 2];
var arrayB = [3, 4];
var newArray = arrayA.concat(arrayB);