Merge pull request lydiahallie#34 from bericp1/patch-1

Clarify Question 39

Author: lydiahallie

README.md

@@ -1180,6 +1180,8 @@ JavaScript only has primitive types and objects.
 
 Primitive types are `boolean`, `null`, `undefined`, `bigint`, `number`, `string`, and `symbol`.
 
+What differentiates a primitive from an object is that primitives do not have any properties or methods; however, you'll note that `'foo'.toUpperCase()` evaluates to `'FOO'` and does not result in a `TypeError`. This is because when you try to access a property or method on a primitive like a string, JavaScript will implicity wrap the object using one of the wrapper classes, i.e. `String`, and then immediately discard the wrapper after the expression evaluates. All primitives except for `null` and `undefined` exhibit this behaviour.
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 </p>
 </details>