Java Double ToRawLongBits()方法及示例

Java Double类中的 doubleToRawLongBits() 方法是java中的一个内置函数，它根据IEEE 754浮点 “双倍格式 “位布局返回指定浮点值的表示， 并保留非数字（NaN）值。

语法

public static long doubleToRawLongBits(double val)

参数： 该方法只接受一个参数val，指定一个双精度浮点数。

返回值： 该函数返回代表浮点数的比特。下面是一些特殊情况。

• 如果参数是正 无穷大 ，结果是 7ff0000000000000L
• 如果参数是负 无穷大 ，则结果为 0xfff0000000000000L
• 如果参数是 NaN ，结果是 0x7ff8000000000000L

下面的程序说明了Double.doubleToRawLongBits()方法的使用。

程序1 :

// Java program to demonstrate
// Double.doubleToRawLongBits() method
 
import java.lang.*;
 
class Gfg1 {
 
    public static void main(String args[])
    {
 
        double val = 1.5d;
 
        // function call
        long answer = Double.doubleToRawLongBits(val);
 
        // print
        System.out.println(val + " in raw long bits: "
                           + answer);
    }
}

输出

1.5 in raw long bits: 4609434218613702656

程序2

// Java program to demonstrate
// Double.doubleToRawLongBits() 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.doubleToRawLongBits(val);
 
        // print
        System.out.println(val + " in raw long bits: "
                           + answer);
 
        // function call
        answer = Double.doubleToRawLongBits(val1);
 
        // print
        System.out.println(val1 + " in raw long bits: "
                           + answer);
 
        // function call
        answer = Double.doubleToRawLongBits(val2);
 
        // print
        System.out.println(val2 + " in raw long bits: "
                           + answer);
    }
}

输出

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

参考资料: https://docs.oracle.com/javase/7/docs/api/java/lang/Double.html#doubleToRawLongBits(双倍)