Dot vs Bracket Notation in Accessing JavaScript Object.

Learn when to use dot and bracket notation in JavaScript.

Dot vs Bracket notation in JavaScript

We can access the property of an object by

• Dot notation
• Bracket notation

Dot Notation

This is the most popular and most used way of accessing the property of an object. This makes code more readable. Dot notation is used most frequently.

Syntax: obj.property_name

var user = {name : "Mark"};
user.name ; // "Mark"

When not to use dot notation

Consider that we are having a property name as 123

var obj = {
 '123' : 123
};

In the above case if we cannot access using

obj.123; 

So, If the property name is not a valid identifier , then we cannot access its value using . notation.

What is an Identifier?

An identifier is a sequence of characters in the code that identifies a variable, function, or property. Generally name of function or variable or property name of Object

What is a valid Identifier?

• In JavaScript, identifiers are…