JSFiddle - React, Tailwind, and code Playground

by Jake Cattrall

JavaScript

function getDistanceFromLatLonInM(lat1, lon1, lat2, lon2) {
    var R = 3959;
    var dLat = deg2rad(lat2 - lat1);
    var dLon = deg2rad(lon2 - lon1);
    var a = Math.sin(dLat / 2) * Math.sin(dLat / 2) + Math.cos(deg2rad(lat1)) * Math.cos(deg2rad(lat2)) * Math.sin(dLon / 2) * Math.sin(dLon / 2);
    var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
    var d = R * c;
    return d;
}

function deg2rad(deg) {
    return deg * (Math.PI / 180);
}