# json.is_boolean · Rell standard library · Chromia Docs (concept)

> pure function is_ boolean(): boolean Determine whether this JSON value is a boolean. Returns true if this JSON value is a boolean, false otherwise Since 0.

Source: https://docs.chromia.com/pages/rell-stdlib/-rell-system-library/root/json/is_boolean/

FUNCTION

# json.is\_boolean

```signature
pure function is_boolean(): boolean
```

Determine whether this JSON value is a boolean.

**Returns**

true if this JSON value is a boolean, false otherwise

Since 0.14.16

[View this page on docs.chromia.com](https://docs.chromia.com/pages/rell-stdlib/-rell%20-system%20-library/%5Broot%5D/json/is_boolean.html)Generated API reference, mirrored from the live docs