# Null Constant

Use Null in Calcul.io. See what this built-in constant represents, enter it in an editable calculation, and review related values and units.

## null

Try it yourself:

```calculio
null
```

[true](https://calcul.io/constants/true/index.md)

[false](https://calcul.io/constants/false/index.md)

---

## null: absent value marker

**null** represents intentional absence of a value. It is not zero, an empty string, or NaN.

## Use

Use [nullish()](https://calcul.io/function/nullish/index.md) to supply a default, [typeOf()](https://calcul.io/function/typeOf/index.md) to inspect data, and [isNumeric()](https://calcul.io/function/isNumeric/index.md) before arithmetic. [NaN](https://calcul.io/constants/NaN/index.md) instead represents an invalid numeric result.

## Caveat

Decide whether null means unknown, not applicable, or missing; those meanings may need different handling.

[All constants](https://calcul.io/constants/index.md)