Extensions
Scalar Functions
```sql
-- ZMFlag for a 2D geometry
SELECT ST_ZMFlag(ST_GeomFromText('POINT(1 1)'));
----
0

-- ZMFlag for a 3DZ geometry
SELECT ST_ZMFlag(ST_GeomFromText('POINT Z(1 1 1)'));
----
2

-- ZMFlag for a 3DM geometry
SELECT ST_ZMFlag(ST_GeomFromText('POINT M(1 1 1)'));
----
1

-- ZMFlag for a 4D geometry
SELECT ST_ZMFlag(ST_GeomFromText('POINT ZM(1 1 1 1)'));
----
3
```  
----  
#### ST_ZMax {#docs:extensions:spatial:functions::st_zmax}