public static long doubleToLongBits(double val)

// 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);
    }
}

1.5 in long bits: 4609434218613702656

// 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);
    }
}

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