Objects and its internal representation in Javascript

In JavaScript, almost “everything” is an object.

• Booleans can be objects (if defined with the new keyword)
• Numbers can be objects (if defined with the new keyword)
• Strings can be objects (if defined with the new keyword)
• Dates are always objects
• Maths are always objects
• Regular expressions are always objects
• Arrays are always objects
• Functions are always objects
• Objects are always objects

All JavaScript values, except primitives, are objects.

Objects are variables too. But objects can contain many values.

Using an Object Literal

var person = {firstName:”Happy”, lastName:”Potter”, age:48};

Using the JavaScript Keyword new

var person = new Object();
person.firstName = “Franklin”;
person.lastName = “Bean”;
person.age = 32;

JavaScript Objects are Mutable

Objects are mutable: They are addressed by reference, not by value.