JavaScript Number.NaN Property

　JavaScript Number Object

Number.NaNThe property is used to represent non-numeric values.

For example, if you try to multiply a number with a string, the returned value is 'NaN'.

The initial value of Number.NaN is Not-A-Number, and the globalNaNthe value is the same.

UsingNumber.isNaN()a function to check if a value is a NaN value.

Because NaN is a static property of Number, you should always use it asNumber.NaN, rather than using it as an attribute of the created Number object.

Syntax:

Number.NaN

var ans =　10　*　'Hello';
;document.getElementById('result').innerHTML = ans;

Browser Compatibility

All browsers fully support the NaN property:

Technical Details

More Examples

Use the Number.isNaN() method to check if the value is a NaN value:

var str = 'Hello world';
var ans = Number(str);　　　//　Convert a string to a number
;if (Number.isNaN(ans)) {
　　　;document.getElementById('result').innerHTML = ans;
}

　JavaScript Number Object