Are +0 and -0 the same?

Question

Reading through the ECMAScript 5.1 specification, +0 and -0 are distinguished.

Why then does +0 === -0 evaluate to true<

Answer 1

In the IEEE 754 standard used to represent the Number type in JavaScript, the sign is represented by a bit (a 1 indicates a negative number).

As a result, there exists both a negative and a positive value for each representable number, including 0.

This is why both -0 and +0 exist.