Number.NaN - JavaScript | MDN
Try it
function clean(x) {
if (x === Number.NaN) {
// Can never be true
return null;
}
if (isNaN(x)) {
return 0;
}
}
console.log(clean(Number.NaN));
// Expected output: 0
Value
The number value NaN.
Property attributes of Number.NaN | |
|---|---|
| Writable | no |
| Enumerable | no |
| Configurable | no |
Description
Because NaN is a static property of Number, you always use it as Number.NaN, rather than as a property of a number value.
Examples
Checking whether values are numeric
js
function sanitize(x) {
if (isNaN(x)) {
return Number.NaN;
}
return x;
}
Specifications
| Specification |
|---|
| ECMAScript® 2026 Language Specification # sec-number.nan |