addMarker

AddMarker is a common function name in mapping and visualization libraries. It refers to the process of creating and placing a marker at a specific geographic coordinate on a map or diagram. The function is usually used as a convenience wrapper that encapsulates the construction of a marker object and its addition to a map layer. Returning the created marker allows subsequent manipulation or removal.

In practice, addMarker is implemented differently across libraries. In Google Maps JavaScript API, the standard way is to create a marker with new google.maps.Marker({ position: {lat, lng}, map: map, title: "...", icon: "..."}). Many samples provide an addMarker helper that wraps this pattern and returns the marker instance. In Leaflet, markers are created with L.marker([lat, lng], options).addTo(map). A project might offer an addMarker(map, coords, options) wrapper to streamline repeated usage.

Common options include coordinates, title or label, icon or custom image, draggable, opacity, zIndex, and a bound popup or tooltip that opens on click. Markers emit events such as click, mouseover, and dragend, enabling interactivity and data display.

The main benefits of an addMarker function are readability, reuse, and consistent styling. For large datasets, developers often combine addMarker with clustering or filtering to manage performance.

See also: Marker, Popup, Map, Clustering, OpenStreetMap, Mapbox, Google Maps, Leaflet.