Add Freeze An Object, Sorta as a javascript til

README.md

@@ -10,7 +10,7 @@ smart people at [Hashrocket](http://hashrocket.com/).
 For a steady stream of TILs from a variety of rocketeers, checkout
 [til.hashrocket.com](https://til.hashrocket.com/).
 
-_586 TILs and counting..._
+_587 TILs and counting..._
 
 ---
 
@@ -217,6 +217,7 @@ _586 TILs and counting..._
 - [Default And Named Exports From The Same Module](javascript/default-and-named-exports-from-the-same-module.md)
 - [Enable ES7 Transforms With react-rails](javascript/enable-es7-transforms-with-react-rails.md)
 - [Expand Emojis With The Spread Operator](javascript/expand-emojis-with-the-spread-operator.md)
+- [Freeze An Object, Sorta](javascript/freeze-an-object-sorta.md)
 - [Globally Install A Package With Yarn](javascript/globally-install-a-package-with-yarn.md)
 - [Immutable Remove With The Spread Operator](javascript/immutable-remove-with-the-spread-operator.md)
 - [Initialize A New JavaScript Project With Yarn](javascript/initialize-a-new-javascript-project-with-yarn.md)

javascript/freeze-an-object-sorta.md

@@ -0,0 +1,44 @@
+# Freeze An Object, Sorta
+
+You can freeze a JavaScript object using `Object.freeze` which will help
+enforce some immutability practices. Don't be fooled though, you can still
+modify arrays and objects in the frozen object.
+
+Here is what the docs have to say:
+
+> The Object.freeze() method freezes an object: that is, prevents new
+> properties from being added to it; prevents existing properties from being
+> removed; and prevents existing properties, or their enumerability,
+> configurability, or writability, from being changed, it also prevents the
+> prototype from being changed.
+
+And here is `Object.freeze` in action:
+
+```javascript
+> const things = {one: "two", hello: "world", cats: ["Von Neumann", "Sosa"]}
+undefined
+> Object.freeze(things)
+{one: "two", hello: "world", cats: Array(2)}
+
+> things.one = "three"
+"three"
+> things.dogs = []
+[]
+> delete things.hello
+false
+
+> things
+{one: "two", hello: "world", cats: Array(2)}
+
+> things.cats.push("Sneaky")
+3
+
+> things
+{one: "two", hello: "world", cats: Array(3)}
+```
+
+See the [MDN
+Docs](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/freeze)
+for more details.
+
+h/t Jake Worth