Number.isNaN

Checks if a number is a special value NaN (not a number).

Syntax

isNaN(number)

Parameters

• number

  A number value.

Return value

Returns true if the number is NaN, false otherwise.

Examples

Number.isNaN(NaN)

true

Number.isNaN(1)

false

Number.isNaN(Math.sqrt(-1))

true

Number.isNaN("a string")

false

// Difference from the global isNaN:
isNaN("a string")

true

See also

• isNaN