A simple usecase to use call, apply and bind

callapplybind.js

'use strict';

var trip1 = {
    destination: "Chennai",
    id: 1
};

var trip2 = {
    destination: "Ooty",
    id: 2
};

var trip3 = {
    destination: "Thanjavur",
    id: 3
};

function launchMap(source, travelmode) {
    window.open('https://www.google.com/maps/dir/?api=1&origin=' + source + '&destination=' + this.destination + '&travelmode=' + travelmode);
}

launchMap.call(trip1,'Coimbatore', 'driving'); //will launch the map direction immediately between Coimbatore to Chennai

launchMap.apply(trip2,['Coimbatore', 'driving']); //will launch the map direction immediately between Coimbatore to Ooty


//do not launch the map, instead return a function, will call it later once we got the source place.

var callLater = launchMap.bind(trip3);
var userLocation;
if (navigator.geolocation) {
    navigator.geolocation.getCurrentPosition(pos => {
        if (pos && pos.coords) {
            var userLocation = pos.coords.latitude + ',' + pos.coords.longitude;
            callLater(userLocation, 'driving');
        }
    });
}