Number.NaN - JavaScript 编辑

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

The source for this interactive example is stored in a GitHub repository. If you'd like to contribute to the interactive examples project, please clone https://github.com/mdn/interactive-examples and send us a pull request.

The source for this interactive example is stored in a GitHub repository. If you'd like to contribute to the interactive examples project, please clone https://github.com/mdn/interactive-examples and send us a pull request.

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 (ECMA-262) The definition of 'Number.NaN' in that specification.

Browser compatibility

BCD tables only load in the browser

See also

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