Travis build: 313

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]
 ```