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Number.NaN

The Number.NaN property represents Not-A-Number. Equivalent of NaN.

You do not have to create a Number object to access this static property (use Number.NaN).

Property attributes of Number.NaN
Writable no
Enumerable no
Configurable no

Examples

Checking whether values are numeric

function sanitise(x) {
  if (isNaN(x)) {
    return Number.NaN;
  }
  return x;
}

Testing against NaN

See Testing against NaN on the NaN page.

Specifications

Browser compatibilityUpdate compatibility data on GitHub

Desktop
Chrome Edge Firefox Internet Explorer Opera Safari
NaN 1 12 1 4 3 1
Mobile
Android webview Chrome for Android Firefox for Android Opera for Android Safari on iOS Samsung Internet
NaN 1 18 4 10.1 1 1.0
Server
Node.js
NaN 0.1.100

See also

  • The global NaN object.
  • The Number object it belongs to.

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Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://wiki.developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/NaN