# Convert linestring to polygon

> Supported in: Batch, Faster, Streaming

Convert a linestring geometry to a polygon geometry. This expression assumes the linestring geometry is closed. If not, the expression will return null.

**Expression categories:** Geospatial

## Declared arguments

* **Expression:** A valid linestring geometry.<br>*Expression\<Geometry>*

**Output type:** *Geometry*

## Examples

### Example 1: Base case

**Argument values:**

* **Expression:** `polygon_points`

| polygon\_points | **Output** |
| ----- | ----- |
| {"type":"LineString","coordinates":\[\[-77.49,38.01],\[-77.47,38.15],\[-77.19,38.14],\[-77.49,38.01]]} | {"type":"Polygon","coordinates":\[\[\[-77.49,38.01],\[-77.47,38.15],\[-77.19,38.14],\[-77.49,38.01]]]} |

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### Example 2: Null case

**Argument values:**

* **Expression:** `polygon_points`

| polygon\_points | **Output** |
| ----- | ----- |
| *null* | *null* |
| {"type":"LineString","coordinates":\[\[-77.49,38.01],\[-77.19,38.14],\[-77.49,38.01]]} | *null* |
| {"type":"LineString","coordinates":\[\[-77.49,38.01],\[-77.19,38.14]]} | *null* |
| {"type":"LineString","coordinates":\[\[-77.49,38.01]]} | *null* |
| {"type":"Polygon","coordinates":\[\[\[-77.49,38.01],\[-77.47,38.15],\[-77.19,38.14],\[-77.49,38.01]]]} | *null* |

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