In JavaScript, NaN stands for Not a Number. It represents a value that is not a valid number. It can be used to check whether a number entered is a valid number or not a number. To assign a variable to NaN value, we can use one of the two following ways.
Syntax:
let a = NaN
// OR
let a = Number.NaN
Example 1: In this example, we will use JavaScript Number NaN Property.
javascript
let monthNumber = 14;if (monthNumber < 1 || monthNumber > 12) { // Assigning monthNumber NaN as // month number is not valid monthNumber = Number.NaN; console.log("Month number should be" + " between 1 and 12");}else { console.log(monthNumber);} |
Output:
Month number should be between 1 and 12
Example 2: Whenever we try to parse a string or “undefined” to an int, it returns NaN.
javascript
console.log(parseInt("hineveropen")); |
Output:
Nan
Example 3: Whenever we try to find square root of a negative number using Math.sqrt function, it returns NaN.
javascript
console.log(Math.sqrt(-1)); |
Output:
NaN
Example 4: Whenever we try to make on operation on NaN, it returns NaN.
javascript
console.log(5 + NaN); |
Output:
NaN
Example 5: Any indeterminate form also returns NaN.
javascript
console.log(0 * Infinity) |
Output:
NaN
Example 6: Any operation other than addition on a string also results in NaN.
javascript
console.log("hi"/5) |
Output:
NaN
Supported Browser:
- Chrome 1 and above
- Edge 12 and above
- Firefox 1 and above
- Internet Explorer 4 and above
- Opera 3 and above
- Safari 1 and above
We have a Cheat Sheet on Javascript Numbers where we covered all the important topics of Javascript to check those please go through JavaScript Number Complete Reference.
