C++ Math isnan()

The function checks whether the number is a Not a Number or not. If the number is NaN, it returns 1 otherwise 0.

Note: The NaN is a non-representable value for floating point elements such as square root of negative number or the result of 0/0.

Syntax

Suppose a number is ‘x’. Syntax would be:

Parameter

x: It is a floating point value.

Return value

It returns 1, if x is NAN otherwise 0.

Example 1

Let’s see the simple example when the value of x is 0.0/0.0.

Output:

value of x is : -nan  isnan(x) : 1     

In this example, isnan(x) determines that the value of x is nan. Therefore, it returns 1.

Example 2

Let’s see the simple example when the value of x is 4.3.

Output:

value of x is : 4.3  isnan(x) : 0     

In this example, isnan(x) function determines that the value of x is not ‘nan’. Therefore, it returns 0 value.