From f9fe8de11a6314525f5b3626aafaea1697e3efbe Mon Sep 17 00:00:00 2001
From: Travis CI <travis@travis-ci.org>
Date: Tue, 26 Dec 2017 13:27:18 +0000
Subject: [PATCH] Travis build: 313

---
 README.md       | 13 ++++++++++---
 docs/index.html | 13 ++++++++++---
 2 files changed, 20 insertions(+), 6 deletions(-)

diff --git a/README.md b/README.md
index 980acdc66..5b770f8c1 100644
--- a/README.md
+++ b/README.md
@@ -795,12 +795,19 @@ const sample = arr => arr[Math.floor(Math.random() * arr.length)];
 
 ### shuffle
 
-Randomizes the order of the values of an array.
+Randomizes the order of the values of an array, in place.
 
-Use `Array.sort()` to reorder elements, using `Math.random()` in the comparator.
+Uses the Fisher-Yates algoritm to reorder the elements of the array, based on the [Lodash implimentation](https://github.com/lodash/lodash/blob/b2ea6b1cd251796dcb5f9700c4911a7b6223920b/shuffle.js)
 
 ```js
-const shuffle = arr => arr.sort(() => Math.random() - 0.5);
+const shuffle = ([...arr]) => {
+  let m = arr.length;
+  while (m) {
+    const i = Math.floor(Math.random() * m--);
+    [arr[m], arr[i]] = [arr[i], arr[m]];
+  }
+  return arr;
+};
 // shuffle([1,2,3]) -> [2,3,1]
 ```
 
diff --git a/docs/index.html b/docs/index.html
index edd49804d..aa9f6c31e 100644
--- a/docs/index.html
+++ b/docs/index.html
@@ -586,9 +586,16 @@ This method also works with strings.</p>
 // sample([3, 7, 9, 11]) -&gt; 9
 </code></pre>
 </div></div><br/><div class="card fluid"><div class="section double-padded"><h3 id="shuffle">shuffle</h3></div><div class="section double-padded">
-<p>Randomizes the order of the values of an array.</p>
-<p>Use <code>Array.sort()</code> to reorder elements, using <code>Math.random()</code> in the comparator.</p>
-<pre><code class="language-js">const shuffle = arr =&gt; arr.sort(() =&gt; Math.random() - 0.5);
+<p>Randomizes the order of the values of an array, in place.</p>
+<p>Uses the Fisher-Yates algoritm to reorder the elements of the array, based on the <a href="https://github.com/lodash/lodash/blob/b2ea6b1cd251796dcb5f9700c4911a7b6223920b/shuffle.js">Lodash implimentation</a></p>
+<pre><code class="language-js">const shuffle = ([...arr]) =&gt; {
+  let m = arr.length;
+  while (m) {
+    const i = Math.floor(Math.random() * m--);
+    [arr[m], arr[i]] = [arr[i], arr[m]];
+  }
+  return arr;
+};
 // shuffle([1,2,3]) -&gt; [2,3,1]
 </code></pre>
 </div></div><br/><div class="card fluid"><div class="section double-padded"><h3 id="similarity">similarity</h3></div><div class="section double-padded">