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

Specification
ECMAScript Language Specification (ECMAScript)
# sec-number.nan

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
NaN
1
12
1
4
3
1
1
18
4
10.1
1
1.0

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