The Float.isNaN() method in Float Class is a built in method in Java returns true if this Float value or the specified float value is Not-a-Number (NaN), or false otherwise.
Syntax:
public boolean isNaN()
or
public static boolean isNaN(float val)
Parameters: he function accepts a single parameter val which specifies the value to be checked when called directly with the Float class as static method. The parameter is not required when the method is used as instance method.
Return Value: It returns true if the val is NaN else it return false.
Below programs illustrate isNaN() method in Java:
Program 1: Using static isNaN() method
// Java code to demonstrate// Float isNaN() method// without parameter  class GFG {    public static void main(String[] args)    {          // first example        Float f1 = new Float(1.0 / 0.0);          boolean res = f1.isNaN();          // printing the output        if (res)            System.out.println(f1 + " is NaN");        else            System.out.println(f1 + " is not NaN");          // second example        f1 = new Float(0.0 / 0.0);          res = f1.isNaN();          // printing the output        if (res)            System.out.println(f1 + " is NaN");        else            System.out.println(f1 + " is not NaN");    }} |
Output:
Infinity is not NaN NaN is NaN
Program 2: Using non-static isNaN() method
// Java code to demonstrate// Float isNaN() method// with parameter  class GFG {    public static void main(String[] args)    {          // first example        Float f1 = new Float(1.0 / 0.0);          boolean res = f1.isNaN(f1);          // printing the output        if (res)            System.out.println(f1 + " is NaN");        else            System.out.println(f1 + " is not NaN");          // second example        f1 = new Float(0.0 / 0.0);          res = f1.isNaN(f1);          // printing the output        if (res)            System.out.println(f1 + " is NaN");        else            System.out.println(f1 + " is not NaN");    }} |
Output:
Infinity is not NaN NaN is NaN
Reference: https://docs.oracle.com/javase/7/docs/api/java/lang/Float.html#isNaN()
