Add access nested object properties question

content/questions/access-nested-object-properties/index.md

@@ -0,0 +1,43 @@
+---
+title: Access nested object properties
+tags:
+  - comparison
+order: 75
+date: Thu Oct 15 2020 14:39:37 GMT+0200 (Central European Summer Time)
+answers:
+  - 'Uncaught TypeError: Cannot read property text of undefined'
+  - 'null'
+  - undefined // correct
+---
+
+Consider the following object. What gets logged?
+
+```javascript
+const person = {
+  	name: {
+		first: {
+			text: 'John'
+		}
+	}
+} 
+
+console.log(person.name.second?.text);
+```
+
+<!-- explanation -->
+
+The expression contains optional chaining syntax, which is a safe way to access nested object properties, even if an intermediate property doesn’t exist. 
+
+The "standard" expression, without `?`:
+
+```javascript
+console.log(person.name.second.text);
+```
+
+will throw an error. 
+
+The `?.` operator functions similarly to the `.` chaining operator, except that instead of causing an error if a reference is nullish (`null` or `undefined`), the expression short-circuits with a return value of `undefined`. When used with function calls, it returns `undefined` if the given function does not exist.
+
+This results in shorter and simpler expressions when accessing chained properties when the possibility exists that a reference may be missing. It can also be helpful while exploring the content of an object when there's no known guarantee as to which properties are required.
+
+Optional chaining was introduced as part of the ES2020 standard.