Question

The marker on click will call a function called calcRoute. I also want to display a text content near the marker when the marker is clicked.

var textContent = "Some text";

var marker = new google.maps.Marker({
            map: map,
            title: MALL.mall.name,
            position: pos
        });

google.maps.event.addListener(marker, 'click', (function () {
            calcRoute();
        }));

Answer 1

Seeing that you’ve tagged your question “infowindow”, you should try it:

var infowindow = new google.maps.InfoWindow({
    content: textContent
});

google.maps.event.addListener(marker, 'click', (function () {
    calcRoute();
    infowindow.open(map, marker);
}));

https://developers.google.com/maps/documentation/javascript/overlays#InfoWindows