Average Lng/Lat NaN Issues - google-maps

Question

I'm an amateur programmer and working on a project I have in mind using the google maps API. Long story short, I'm trying to create a variable with the average longitude and latitude of n number of points. I'm to the point that I have an array of the lng/lat coordinates, but I'm struggling to convert them into a format that I can use as input for a google maps LatLng method.
I've referenced this SO question, Find the average (center) of lats/lngs, and numerous other websites for a month now, but I haven't been able to understand or implement a solution. I feel like I'm missing the simple stuff, but I've been banging my head against this for a month, and not getting anywhere. Any advice or help with this would be appreciated.
//GOOGLE MAPS API SCRIPTS
var streetarray = document.getElementsByName("street");
var cityarray = document.getElementsByName("city");
var geocoder;
var map;
var results;
var mapArray = new Array();
var avgLat;
var avgLng;
function initialize() {
geocoder = new google.maps.Geocoder();
var latlng = new google.maps.LatLng(-34.397, 150.644);
var mapOptions = {
zoom: 8,
//centered on Carrollton, Texas -- Change lat,long values to change initial map area
center:
new google.maps.LatLng(32.999173, -96.897413)
}
//change Id reference to the div/container that contains the google map
map = new google.maps.Map(document.getElementById('map'), mapOptions);
}
function codeAddress() {
//Loop through and concate street and city values to find long,lat values for all fields
for (var cName = 0; cName < namearray.length; cName++){
var address = streetarray[cName].value + cityarray[cName].value;
//start geocode copy & paste text from API reference
geocoder.geocode( { 'address': address}, function(results, status) {
if (status == google.maps.GeocoderStatus.OK) {
var results = results[0].geometry.location;
map.setCenter(results);
var marker = new google.maps.Marker({
map: map,
position: results,
});
//Push lng/lat locations to the mapArray
mapArray.push(results);
//Loop through mapArray to add Lat/Lng values, and then divide by j (number of locations) to find the average
for (var i in mapArray) {
var avgLat = 0;
var avgLng = 0;
var j = 0;
var avgLat = (avgLat + mapArray[i][1]);
var avgLng = (avgLng + mapArray[i][2]);
console.log(mapArray, avgLat, avgLng);
j++;
}
avgLat = avgLat / j;
avgLng = avgLng / j;
var markerCircle = new google.maps.Circle({
center: results,
radius: 15000,
strokeColor:"#0000FF",
strokeOpacity:0.8,
strokeWeight:2,
fillColor:"#0000FF",
fillOpacity:0.4
})
markerCircle.setMap(map);
} else {
alert('Geocode was not successful for the following reason: ' + status);
}
});
}}

Answer 1

2 issues:
results[0].geometry.location is not an array, it's an object(a google.maps.LatLng). Use the methods lat() and lng() to retrieve latitude and longitude
var avgLat = 0;
var avgLng = 0;
var j = 0;.
You must move this to outside of the loop, otherwise the variables will be cleared on each loop.