Why is the value 'null' considered a number in JavaScript?

In JavaScript, null is a primitive value.

The typeof operator returns a string indicating the type of the operand. Historically, typeof null returns "object". This is considered a bug in the language's design, present since the early versions of JavaScript and maintained for backward compatibility.

It's important to understand that null is not considered a number. It is not a numeric primitive (number, bigint). The "object" result from typeof null does not mean that null is an object or a number.

Comparing null with numbers has its nuances when using loose equality operators (==) and comparison operators (<, >, <=, >=).

• null == undefined returns true.

• When comparing null with numbers using comparison operators (<, >, <=, >=), null is implicitly converted to 0.

  // null is implicitly converted to 0 in comparisons
  console.log(null > 0);  // false
  console.log(null == 0); // false
  console.log(null >= 0); // true
  

Thus, although typeof null returns "object", and null can be coerced to 0 in certain comparison contexts, this does not mean that null is "considered a number" in the general sense. It is more of a historical quirk and rules of implicit type coercion.