---
title: ifNull
description: Pipeline expression helper that returns a fallback when a value is null or absent.
next: /firestore/pipelines/switch-on
previous: /firestore/pipelines/current-document
---

`ifNull()` returns a fallback when the first argument evaluates to **null** or is **absent**. Unlike [`ifAbsent()`](/firestore/pipelines), which only substitutes missing fields, `ifNull()` also replaces explicit `null` values stored on the document.

Import from the pipelines entry point:

```js
import { ifNull, field, constant } from '@react-native-firebase/firestore/pipelines';
```

# Basic example

```js
import { getFirestore } from '@react-native-firebase/firestore';
import { execute, field, constant, ifNull } from '@react-native-firebase/firestore/pipelines';

const db = getFirestore('your-enterprise-database-id');

const snapshot = await execute(
  db
    .pipeline()
    .collection('users')
    .select(ifNull(field('displayName'), constant('Anonymous')).as('displayName')),
);

snapshot.results.forEach(row => {
  console.log(row.data().displayName);
});
```

# Fluent form

```js
field('displayName').ifNull(constant('Anonymous')).as('displayName');
```

# Comparison with ifAbsent

| Helper     | Missing field | Explicit `null` on document |
| ---------- | ------------- | --------------------------- |
| `ifAbsent` | fallback      | keeps `null`                |
| `ifNull`   | fallback      | fallback                    |

Use `ifNull` when you want one expression to cover both absent and null values.

# Upstream reference

See the [firebase-js-sdk `ifNull` declaration](https://firebase.google.com/docs/reference/js/firestore_pipelines#ifnull) for full overload signatures.