Incredibly good work!
“Thanks!” Bob said as he hopped on his bike. “I’ll be following this road to the observatory then!”
The last couple of exercises introduced quite a few things, namely, way and the out geom modificator.
A Way is another OSM element (like node) that describes a linear feature or area. Just accept that a way can also define areas for now. The relevant info that we need to learn is that a way is usually used to define roads, streams and highways, among other things. If you need to query for a route, or something that you think can’t be defined as a single ‘point’, it’s most likely a way element!
In OSM, Ways are represented just as a set of points. If you think about it, we can use a couple of points to define a line (which can be used to define routes).
Since ways are represented internally as just a set of points, a way is actually just an ordered list of nodes! Awesome right? Because of this, we can actually query for the individual nodes in a way, though that’s not something we will do for now.
You might have noticed that we used out geom; instead of our usual out statement in our latest query. What’s up with that?
To understand that, let’s talk about out first. The out statement is an called action, the only action in the Overpass QL. What it does is to take the input set (the result set/data that preceeds it) and print it, so we can use the data (which we see in the map viewer).
So far, we have only used the bare out statement. What happens if we used out instead of out geom in our last query? Let’s try that!
out statement by removing the geom modificator. Be careful not to remove the semicolon!