Add Immutable Remove With The Spread Operator as a javascript til

README.md

@@ -7,7 +7,7 @@ variety of languages and technologies. These are things that don't really
 warrant a full blog post. These are mostly things I learn by pairing with
 smart people at [Hashrocket](http://hashrocket.com/).
 
-_362 TILs and counting..._
+_363 TILs and counting..._
 
 ---
 
@@ -121,6 +121,7 @@ _362 TILs and counting..._
 - [Computed Property Names In ES6](javascript/computed-property-names-in-es6.md)
 - [Create An Array Containing 1 To N](javascript/create-an-array-containing-1-to-n.md)
 - [Enable ES7 Transforms With react-rails](javascript/enable-es7-transforms-with-react-rails.md)
+- [Immutable Remove With The Spread Operator](javascript/immutable-remove-with-the-spread-operator.md)
 - [Random Cannot Be Seeded](javascript/random-cannot-be-seeded.md)
 - [Splat Arguments To A Function](javascript/splat-arguments-to-a-function.md)
 - [Throttling A Function Call](javascript/throttling-a-function-call.md)

javascript/immutable-remove-with-the-spread-operator.md

@@ -0,0 +1,24 @@
+# Immutable Remove With The Spread Operator
+
+ES6 introduces the [spread
+operator](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Spread_operator)
+which allows you to expand arrays in place for function calls, array
+composition, array destructuring, etc. One thing the spread operator allows
+you to concisely do with array composition is perform immutable operations
+on arrays. For instance, to remove an item from an array by index, you can
+throw together the following function.
+
+```javascript
+const remove = (items,index) => {
+  return [...items.slice(0,index),
+          ...items.slice(index+1,items.length)];
+};
+
+const list = [1,2,3,4,5];
+remove(list, 2);
+// [1,2,3,4]
+list
+// [1,2,3,4,5]
+```
+
+It only took a couple lines of code and immutability is baked in.