How can I create an array that contains latitude and longitude and use for loop to mark the positions on google map in android

Question

I've just started coding in android and after a very long time I got my google map to work and have been able to put markers on it.

What I want to do next is create a array of latlng and use for loop to put a marker on the google maps. I cannot figure out how to do. Could someone please help me. I have done the following so far.

ArrayList<Markers> mMap = new ArrayList<Markers>();

public ArrayList arraylist[] = {new ArrayList(
                            new LatLng(30.243442, -1.432320)),

I would like to expand this later, hence I would like to use array list.

I understand how the for loop works, but I cannot work out how to implement it with this as I cannot get those locations from array to tag on my map.

      for (i = 0; i < cars.length; i++) {
mMap.addMarker(new MarkerOptions()
        .position(new LatLng(10, 10))
        .title("Hello world"));
        }

I am completely lost from this stage. Could someone please guide and help me out.

Thanks.

Solution

Firstly, you are wanting an array that stores the LatLng object. So, declare one like so:

ArrayList<LatLng> locations;

And you also need to initialise your ArrayList:

locations = new ArrayList();

Now you can add locations to the array, using the ArrayList.add method:

locations.add(new LatLng(latitude, longitude));

Now that you have an ArrayList filled with some LatLng's, you can iterate over them using a foreach loop, like so:

for(LatLng location : locations){ 
    mMap.addMarker(new MarkerOptions() 
        .position(location)
        .title(...)
}

The above basically reads as:

For each location in the locations ArrayList, add a new marker, where the position of the marker is the location we're retrieving from out array

Tying it all together:

ArrayList<LatLng> locations = new ArrayList();
locations.add(new LatLng(30.243442, -1.432320));
locations.add(new LatLng(... , ...));
.
.
.

for(LatLng location : locations){
    mMap.addMarker(new MarkerOptions()
        .position(location)
        .title(...)
}