Double doubleToLongBits() method in Java with examples

The java.lang.Double.doubleToLongBits() method of Java Double class is a built-in function in java that returns a representation of the specified floating-point value according to the IEEE 754 floating-point “double format” bit layout.

Syntax:

public static long doubleToLongBits(double val)

Parameter: The method accepts only one parameter val which specifies a double precision floating-point number.

Return Values: The function returns the bits that represent the floating-point number. Below are the special cases:

• If the argument is positive infinity, the result is 7ff0000000000000L.
• If the argument is negative infinity, the result is 0xfff0000000000000L.
• If the argument is NaN, the result is 0x7ff8000000000000L.

Below programs illustrates the use of java.lang.Double.doubleToLongBits() method:

Program 1:

// Java program to demonstrate
// Double.doubleToLongBits() method

import java.lang.*;

class Gfg1 {

    public static void main(String args[])
    {

        double val = 1.5d;

        // function call
        long answer = Double.doubleToLongBits(val);

        // print
        System.out.println(val + " in long bits: "
                           + answer);
    }
}

Output:

1.5 in long bits: 4609434218613702656

Program 2:

// Java program to demonstrate
// Double.doubleToLongBits() method

import java.lang.*;

class Gfg1 {

    public static void main(String args[])
    {

        double val = Double.POSITIVE_INFINITY;
        double val1 = Double.NEGATIVE_INFINITY;
        double val2 = Double.NaN;

        // function call
        long answer = Double.doubleToLongBits(val);

        // print
        System.out.println(val + " in long bits: "
                           + answer);

        // function call
        answer = Double.doubleToLongBits(val1);

        // print
        System.out.println(val1 + " in long bits: "
                           + answer);

        // function call
        answer = Double.doubleToLongBits(val2);

        // print
        System.out.println(val2 + " in long bits: "
                           + answer);
    }
}

Output:

Infinity in long bits: 9218868437227405312
-Infinity in long bits: -4503599627370496
NaN in long bits: 9221120237041090560

Reference: https://docs.oracle.com/javase/7/docs/api/java/lang/Double.html#doubleToLongBits(double)