Are null and undefined equal in js?

null and undefined are not equal in JavaScript for the following reasons: null represents an empty object or a non-existent value, while undefined represents an unassigned variable or property. After the == operator converts null and undefined to numbers, null is 0 and undefined is NaN. NaN is not equal to any number, including itself, so null and undefined are not equal under the == operator.

Are null and undefined equal in js?

No, null and undefined are not equal in js.

Detailed description:

null is a special value in JavaScript, representing an empty object or a non-existent value. undefined is also a special value, indicating that a variable or property has not been assigned a value.

In JavaScript, the == operator checks whether two values ​​are equal. However, the == operator has special handling for null and undefined. == automatically converts null and undefined to numbers and then compares the numbers for equality.

After conversion, null becomes 0 and undefined becomes NaN. NaN is a special value that represents not-a-number, which is not equal to any other number, including itself.

Therefore, the == operator returns false when comparing null and undefined.

Example:

<code class="js">console.log(null == undefined); // false
console.log(null === undefined); // false</code>

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