> For the complete documentation index, see [llms.txt](https://osl.mistium.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://osl.mistium.com/packages/utilities/set.md).

# set

> A set type

Use `set` when you need a collection of unique values with membership checks.

```javascript
import "osl/set"
```

## Example

```javascript
import "osl/set"

set names = set()
names.add("ada")
log names.contains("ada")
```

## API reference

### `Set` values

Methods available on `Set` values returned by this package or constructed by the language.

| Method                   | Returns   | Description                          |
| ------------------------ | --------- | ------------------------------------ |
| `value.add(v: any)`      | `*Set`    | Runs the add operation.              |
| `value.delete(v: any)`   | `error`   | Deletes a value.                     |
| `value.contains(v: any)` | `boolean` | Runs the contains operation.         |
| `value.size()`           | `number`  | Returns the number of stored values. |
| `value.clear()`          | `void`    | Clears all stored values.            |
| `value.toArr()`          | `array`   | Converts the value to an array.      |

## Notes

* Standard-library imports accept both `import "osl/set"` and `import "set"`.
* Return values such as `array` and `object` are regular OSL values unless a returned object section says otherwise.