QGIS/resources/function_help/json/is_closed

{
  "name": "is_closed",
  "type": "function",
  "groups": ["GeometryGroup"],
  "description": "Returns TRUE if a line string is closed (start and end points are coincident), or false if a line string is not closed. If the geometry is not a line string then the result will be NULL.",
  "arguments": [{
    "arg": "geometry",
    "description": "a line string geometry"
  }],
  "examples": [{
    "expression": "is_closed(geom_from_wkt('LINESTRING(0 0, 1 1, 2 2)'))",
    "returns": "FALSE"
  }, {
    "expression": "is_closed(geom_from_wkt('LINESTRING(0 0, 1 1, 2 2, 0 0)'))",
    "returns": "TRUE"
  }],
  "tags": ["points", "start", "closed", "end", "coincident", "result", "false", "line"]
}