voluptasmollitia/docs-exp/firestore_.documentchange.md

Monorepo for the Firebase JavaScript SDK

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[Home](./index.md) &gt; [@firebase/firestore](./firestore.md) &gt; [/](./firestore_.md) &gt; [DocumentChange](./firestore_.documentchange.md)

## DocumentChange interface

A `DocumentChange` represents a change to the documents matching a query. It contains the document affected and the type of change that occurred.

<b>Signature:</b>

```typescript
export declare interface DocumentChange<T = DocumentData> 
```

## Properties

|  Property | Type | Description |
|  --- | --- | --- |
|  [doc](./firestore_.documentchange.doc.md) | [QueryDocumentSnapshot](./firestore_.querydocumentsnapshot.md)<!-- -->&lt;T&gt; | The document affected by this change. |
|  [newIndex](./firestore_.documentchange.newindex.md) | number | The index of the changed document in the result set immediately after this <code>DocumentChange</code> (i.e. supposing that all prior <code>DocumentChange</code> objects and the current <code>DocumentChange</code> object have been applied). Is -1 for 'removed' events. |
|  [oldIndex](./firestore_.documentchange.oldindex.md) | number | The index of the changed document in the result set immediately prior to this <code>DocumentChange</code> (i.e. supposing that all prior <code>DocumentChange</code> objects have been applied). Is <code>-1</code> for 'added' events. |
|  [type](./firestore_.documentchange.type.md) | [DocumentChangeType](./firestore_.documentchangetype.md) | The type of change ('added', 'modified', or 'removed'). |