How to display the nearest latitude and longitude to my location using javascript?

Question

I am new in stack overflow and I was wondering if anyone could help me with javascript and getting the nearest latitude and longitude to my current location.

I have an API that stores latitude and longitude coordinates and I have saved those in javascript variables, and also have my current location saved in variables.

I need to somehow sort the list of latitude and longitude coordinates from my list to display the nearest one to my current location.

Does this make sense?

Answer 1

Javascript function to calculate distance

$nearest=1; //Limit within 1 KM.

$("#jobnews").html("<h2>Results:</h2>"); 
$.each(info.companies.company, function(index, job)
{ 
    var lat = list.location.lat; 
    var lng = list.location.lng; 
    var nam = current.location.lat; 
    var cou = current.location.lng; 
    //In below line we will get the distance between current and given coordinates.
    var d=distance(nam, cou, lat, lng, "K");
    //Check the d is within 1 KM, If so then add it to map.
    if(nearest>d)
    {
        var map = "</p><img src='maps.google.com/maps/api/staticmap?center="; + lat + "," +lng +"&zoom=17&size=400x300&key="+key+"&maptype=roadmap&visual_refresh=true&markers=‌​color:red|"+lat+","+lng+"&sensor=true'width='300' height='280'alt='Map of your location.'/>"; 
        var nearestList = "<div><h3>DISPLAY INFO: "+lis.name+link+nam+lat+lng+cou+map+"</div>"; 
    }
}  

function distance(lat1, lon1, lat2, lon2, unit) {
    var radlat1 = Math.PI * lat1/180
    var radlat2 = Math.PI * lat2/180
    var radlon1 = Math.PI * lon1/180
    var radlon2 = Math.PI * lon2/180
    var theta = lon1-lon2
    var radtheta = Math.PI * theta/180
    var dist = Math.sin(radlat1) * Math.sin(radlat2) + Math.cos(radlat1) * Math.cos(radlat2) * Math.cos(radtheta);
    dist = Math.acos(dist)
    dist = dist * 180/Math.PI
    dist = dist * 60 * 1.1515
    if (unit=="K") { dist = dist * 1.609344 }
    if (unit=="N") { dist = dist * 0.8684 }
    return dist
}        

Passed to function:

lat1, lon1 = Latitude and Longitude of point 1 (in decimal degrees)
lat2, lon2 = Latitude and Longitude of point 2 (in decimal degrees)
unit = the unit you desire for results
where: 'M' is statute miles
'K' is kilometers (default)
'N' is nautical miles

Answer 2

You may want to include the Geolib library.

The first example demonstrates the getDistance function. If you combine this with map and sort you can get what you want in a couple of lines:

var current = {lat: 10, lng: 20}
var coords = [{lat: 5, lng: 5}, {lat: 10.2, lng: 19.6}, {lat: 60, lng: 10}];

var distFromCurrent = function(coord) {
    return {coord: coord, dist: geolib.getDistance(current, coord)};
}

var closest = coords.map(distFromCurrent).sort(function(a,b)  { return a.dist - b.dist })[0];

console.log("Closest: " + closest.coord.lat + ", " + closest.coord.lng);