How to get the closest latitude longitude distance

hey, do you guys need this javascript function? if you need you can take it below, I got this function from stackoverflow

code :

function getDistanceFromLatLonInKm(lat1, lon1, lat2, lon2) {
  var R = 6371; // Radius of the earth in km
  var dLat = deg2rad(lat2 - lat1); // deg2rad below
  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; // Distance in km
  return d;
}

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

var centerLat = 52.5167;
var centerLng = 13.3933;

var posts = [{
    name: 'PostA',
    latitude: '52.5167',
    longitude: '13.3833',
  },
  {
    name: 'PostB',
    latitude: '52.9667',
    longitude: '13.7167',
  },
  {
    name: 'PostC',
    latitude: '26.7767',
    longitude: '18.4567',
  }
];

let closePosts = [];

posts.forEach((post) => {
  if (getDistanceFromLatLonInKm(centerLat, centerLng, post.latitude, post.longitude) < 5) {
    closePosts.push(post);
  }
});

console.log(closePosts)