{
  "name": "$z",
  "type": "function",
  "groups": ["GeometryGroup"],
  "description": "Returns the z value of the current point feature if it is 3D. If the feature is a multipoint feature, then the z value of the first point will be returned.",
  "examples": [{
    "expression": "$z",
    "returns": "123"
  }],
  "tags": ["first", "point", "current", "multipoint", "altitude", "3D"]
}