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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 compatibility

Desktop Mobile Server
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet Deno Node.js
NaN
1
12
1
4
3
1
1
18
4
10.1
1
1.0
1.0
0.10.0

See also

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

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https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/NaN