Dot and Square Bracket Notation

Question

I\'m trying to understand the difference between the Dot and the Square Bracket Notation. While going through various examples here on SO and on some other sites, I came acr

Answer 1

Accessing/Creation of properties from/in a JavaScript object can be done in two ways

1. Using Dot notation
2. Using Square Bracket notation

Whenever some property is not defined i.e. not present in the object and you try to access it, you will get undefined (obviously, because it's not there).

So, in the first example you are accessing a property and in the second example you are creating a property. Therefore, replacing the notation did not affect the code in the second example.