From 0291c3096f5d1c2b7b32a994da3d9722133a1591 Mon Sep 17 00:00:00 2001
From: Ben Noordhuis <info@bnoordhuis.nl>
Date: Tue, 15 Oct 2019 12:22:13 +0200
Subject: [PATCH] fixup! add example

---
 doc/api/crypto.md | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/doc/api/crypto.md b/doc/api/crypto.md
index fe5ddad29367ac..bc8d0d83d84ecc 100644
--- a/doc/api/crypto.md
+++ b/doc/api/crypto.md
@@ -1061,6 +1061,23 @@ specify the desired output length in bytes.
 An error is thrown when an attempt is made to copy the `Hash` object after
 its [`hash.digest()`][] method has been called.
 
+```js
+// Calculate a rolling hash.
+const crypto = require('crypto');
+const hash = crypto.createHash('sha256');
+
+hash.update('one');
+console.log(hash.copy().digest('hex'));
+
+hash.update('two');
+console.log(hash.copy().digest('hex'));
+
+hash.update('three');
+console.log(hash.copy().digest('hex'));
+
+// Etc.
+```
+
 ### hash.digest(\[encoding\])
 <!-- YAML
 added: v0.1.92