Java Double isNaN() Method

The isNaN() method of Java Double class returns true:

If the value of this Object is Not-a-Number (NaN).
If the argument passed is Not-a-Number (NaN).
Otherwise, the method returns false.

Syntax

1.public boolean isNaN()
2.public static boolean isNaN(double v)

Parameters

1.NA

2.' v ' is the double value to be tested.

Return value

The isNaN() method returns true if the argument specified is Not-a-Number(NaN), else returns false.

Example 1

public class Double_isNaNMethodExample1 {
    public static void main(String[] args) {
       Double d1=new Double(7.0/0.0);
       Double d2=new Double(0.0-0.0);
       Double d3=new Double(55.0*0.0/0.0);
       System.out.println(d1 +"-" +d1.isNaN());
       System.out.println(d2 +"-" +d2.isNaN());
       System.out.println(d3 +"-" +d3.isNaN());
    }
}

Test it Now

Output:

Infinity-false
0.0-false
NaN-true

Example 2

import java.util.Scanner;
public class Double_isNaNMethodExample2 {
    public static void main(String[] args) 
        Scanner scanner = new Scanner(System.in);
        System.out.println(" Enter Positive double number = ");
        Double d1 = scanner.nextDouble();
        Double d2 = d1/0.0f - d1/0.0f;
        System.out.println("1. "+d1+"/0.0 - "+  d1+"/0.0 = "+d2+" value is " +d2.isNaN());
        //isNaN() method will return true
        Double d3 = d1/0.0f * 0.0f;
        System.out.println("2. "+d1+"/0.0 *"+ " 0.0 = "+d3+" value is " +d3.isNaN());
       //calling static isNaN() method
        Double d4 = d1*0f / 0f;
        System.out.println("3. "+d1+"*0.0 / "+  "0.0 = "+d4+" value is " +Double.isNaN(d4));
        Double d5 = Double.NaN - 768943453;
        System.out.println("4. "+Double.NaN+" - 768943453"+ " = "+d5+" value is " +d5.isNaN());
   }
}

Test it Now

Output:

Enter Positive double number = 
323
1. 323.0/0.0 - 323.0/0.0 = NaN value is true
2. 323.0/0.0 * 0.0 = NaN value is true
3. 323.0*0.0 / 0.0 = NaN value is true
4. NaN - 768943453 = NaN value is true
BUILD SUCCESSFUL (total time: 8 seconds)

Example 3

import java.util.Scanner;
public class Double_isNaNMethodExample3 {   
    public static void main(String[] args) {   
       Scanner scanner = new Scanner(System.in);
        System.out.println("Enter two double no.\n1. Enter Positive double number = ");
        Double d1 = scanner.nextDouble();
        double d2 = (float) Math.sqrt(d1);
        System.out.println("Ans. Square root of " + d1 + " value = " + d2);
        System.out.println("2. Enter Negative double number =");
        Double d3 = scanner.nextDouble();
        double d4 = (double) Math.sqrt(d3);
        // cube root of negative isNan
        if (Double.isNaN(d4)) {
            System.out.println("Ans. Square root of " + d3 + " value = " + d4);
        }
        else{
            System.out.println("Plz enter a negative integer.");
        }
    }
}

Test it Now

Output:

Enter two double no.
1. Enter Positive double number = 
94
Ans. Square root of 94.0 value = 9.69536018371582
2. Enter Negative double number =
-556
Ans. Square root of -556.0 value = NaN
BUILD SUCCESSFUL (total time: 16 seconds)

Next TopicJava Double

← prev next →