Update deepClone.md

snippets/deepClone.md

@@ -3,12 +3,14 @@ title: deepClone
 tags: object,recursion,intermediate
 ---
 
-Creates a deep clone of an object.
+Creates a deep clone of an object. 
+Clones primitives, arrays and objects, excluding class instances.
 
 Use recursion.
 Check if the passed object is `null` and, if so, return `null`.
 Use `Object.assign()` and an empty object (`{}`) to create a shallow clone of the original.
 Use `Object.keys()` and `Array.prototype.forEach()` to determine which key-value pairs need to be deep cloned.
+If the object is an `Array`, set the `clone`'s `length` to that of the original and use `Array.from(clone)` to create a clone.
 
 ```js
 const deepClone = obj => {
@@ -17,15 +19,15 @@ const deepClone = obj => {
   Object.keys(clone).forEach(
     key => (clone[key] = typeof obj[key] === 'object' ? deepClone(obj[key]) : obj[key])
   );
-  return Array.isArray(obj) && obj.length
-    ? (clone.length = obj.length) && Array.from(clone)
-    : Array.isArray(obj)
-    ? Array.from(obj)
-    : clone;
+  if (Array.isArray(obj)) {
+    clone.length = obj.length;
+    return Array.from(clone);
+  }
+  return clone;
 };
 ```
 
 ```js
 const a = { foo: 'bar', obj: { a: 1, b: 2 } };
 const b = deepClone(a); // a !== b, a.obj !== b.obj
-```
+```