JavaScript Number.isNaN() Method

Last Updated : 04 Sep, 2020

Below is the example of the Number.isNaN() Method.

Example:

<script>
function GFGFun() {
  var res = "";
  res = res + Number.isNaN(123);
document.write(res);

}
GFGFun();
</script>
Output:
```
false
```

The Number.isNan method in JavaScript is used to determines whether the passed value is NaN(Not a Number) and is of the type “Number”.
In JavaScript, the value NaN is considered a type of number.

Syntax:

Number.isNaN(value)

Parameters Used:
1. Value :It is the value which is to be tested for NaN.

Return Value:
The Number.isNaN() method in JavaScript returns true if the passed value is Nan and is of the type number,else it returns false.

Examples:

Input : 0/0
Output : true
     
Input : 213
Output : false

Input : '213'
Output : false

Input : 'hello'
Output : false

Input : NaN
Output : true

When an equation resulting in infinite value is passed as a parameter.
<script>
function GFGFun() {
  var res = "";
  res = res + Number.isNaN(0/0);
document.write(res);

}
GFGFun();
</script>
Output:
```
Output : true
```
When a number is passed as a parameter.
<script>
function GFGFun() {
  var res = "";
  res = res + Number.isNaN(321);
document.write(res);

}
GFGFun();
</script>
Output:
```
Output : false
```
When a number in string representation is passed as a parameter.
<script>
function GFGFun() {
  var res = "";
  res = res + Number.isNaN(213);
document.write(res);

}
GFGFun();
</script>
Output:
```
Output : false
```
When a string is passed as a parameter.
<script>
function GFGFun() {
  var res = "";
  res = res + Number.isNaN("hello");
document.write(res);

}
GFGFun();
</script>
Output:
```
Output : false
```
When Nan is passed as a parameter.
<script>
function GFGFun() {
  var res = "";
  res = res + Number.isNaN(NaN);
document.write(res);

}
GFGFun();
</script>
Output:
```
Output : true
```

Supported Browsers:

Google Chrome
Internet Explorer 12
Firefox 32
Apple Safari 9
Opera 22

My Personal Notes

Related Articles

JavaScript Number.isNaN() Method