Jul 8, 2025 · To tell if a value is NaN, use Number.isNaN() or isNaN() to most clearly determine whether a value is NaN — or, since NaN is the only value that compares unequal to itself, you can perform a …

Description In JavaScript, NaN is short for "Not-a-Number". In JavaScript, NaN is a number that is not a legal number. The Global NaN property is the same as the Number.Nan property.

Apr 16, 2010 · The NaN (Not-a-Number) is a weirdo Global Object in javascript frequently returned when some mathematical operation failed. You wanted to check if NaN == null which results false.

In this tutorial, you'll learn about the JavaScript NaN, how to check if a value is NaN, and how to handle NaN effectively.

Jul 15, 2025 · NaN, which stands for "Not a Number," is a special value in JavaScript that shows up when a mathematical operation can't return a valid number. This can happen if you try something like …

There are several operations in JavaScript that can produce NaN. Understanding these scenarios will help you anticipate and prevent NaN -related bugs in your code.

Oct 18, 2025 · Operations on number type values in JavaScript are represented as double-precision floating-point numbers (double) to perform operations on them according to the IEEE 754 standard.

May 18, 2025 · A detailed look at how JavaScript processes special values like NaN, Infinity, and -0, including how comparisons and arithmetic behave with each one.

Sep 26, 2025 · Use Number.isNaN () to reliably check if a value is NaN (Not a Number) in JavaScript with proper type safety.

Jul 8, 2025 · The isNaN() function answers the question "is the input functionally equivalent to NaN when used in a number context". If isNaN(x) returns false, you can use x in an arithmetic expression …