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## Short answer

```javascript
typeof null === "object"
```

Result: `"object"`

---

## Why this happens

This is a **historical bug** in JavaScript,
which appeared as far back as the very first version of the language (1995)
and **stuck around for the sake of compatibility**.

---

### Historical reason

In early versions of JS, values were stored as **32-bit tagged data**:

- the first **3 bits** indicated the **data type**
- the remaining **29 bits** held the value itself

Objects used the **type tag** `000`
(three zeros at the start of the 32-bit value).

And for `null`, **the entire value consisted of zeros** (`0x00`).

So when checking `typeof null`, the engine saw:
"ah, the first three bits are `000` → this is an object".

That's how this came to be:

```javascript
typeof null // "object"
```

---

## Why this was not fixed

Because millions of old scripts across the internet
may depend on this behavior.
Fixing it would cause massive breakage.

> So the ECMAScript specification left this as a **"known bug"**,
> but **officially documented** it.

---

## How to correctly check for `null`

Because of this bug, **you cannot rely only on** `typeof` to check for `null`.

### Incorrect:

```javascript
if (typeof value === 'object') {
  // could be null!
}
```

### Correct:

```javascript
if (value === null) {
  console.log('This is null');
}
```

or if you want to distinguish null from other objects:

```javascript
if (typeof value === 'object' && value !== null) {
  console.log('This is an object, but not null');
}
```

---

## Illustrative example

```javascript
console.log(typeof null);        // "object"
console.log(typeof {});          // "object"
console.log(typeof []);          // "object"
console.log(null === {});        // false
console.log(null === undefined); // false
```

> All three (`null`, `{}`, `[]`) return `"object"`,
> but these are **different data types**.

---

## Summary

| Check | Result | Explanation |
|---|---|---|
| `typeof null` | `"object"` | A historical implementation bug |
| `null === null` | `true` | The value equals itself |
| `typeof undefined` | `"undefined"` | Expected behavior |
| `typeof {}` | `"object"` | A genuine object |
| `typeof []` | `"object"` | An array is a subtype of object |

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