Java中的整数reverseBytes()方法

Java.lang.Integer.reverseBytes(int a) 是一个内置方法，它返回通过反转指定 int 值的二进制补码表示中的字节顺序获得的值。

句法 ：

public static int reverseBytes(int a)

参数：该方法采用一个整数类型的参数a ，其字节要反转。

返回值：该方法将返回指定int值中的字节反转得到的值。

例子：

Input: 75
Output: 1258291200
Explanation:
Consider an integer a = 75 
Binary Representation = 1001011
Number of one bit = 4 
After reversing the bytes we get = 1258291200

Input: -43
Output: -704643073

下面的程序说明了Java.lang.Integer.reverseBytes() 方法：
程序 1：对于正数。

// Java program to illustrate the
// Java.lang.Integer.reverseBytes() method
import java.lang.*;
  
public class Geeks {
  
    public static void main(String[] args)
    {
  
        int a = 61;
        System.out.println(" Integral Number = " + a);
  
        // It will return the value obtained by reversing the bytes in the
        // specified int value
        System.out.println("After reversing the bytes we get = " + 
        Integer.reverseBytes(a));
    }
}

输出：

Integral Number = 61
After reversing the bytes we get = 1023410176

程序 2：对于负数。

// Java program to illustrate the
// Java.lang.Integer.reverseBytes() method
import java.lang.*;
  
public class Geeks {
  
    public static void main(String[] args)
    {
  
        int a = -43;
        System.out.println(" Integral Number = " + a);
  
        // It will return the value obtained by reversing the bytes in the
        // specified int value
        System.out.println("After reversing the bytes we get = " + 
        Integer.reverseBytes(a));
    }
}

输出：

Integral Number = -43
After reversing the bytes we get = -704643073

程序 3：对于十进制值和字符串。
注意：当十进制值和字符串作为参数传递时，它会返回错误消息。

// Java program to illustrate the
// Java.lang.Integer.reverseBytes() method
import java.lang.*;
  
public class Geeks {
  
    public static void main(String[] args)
    {
  
        int a = 37.81;
        System.out.println(" Integral Number = " + a);
        // It will return the value obtained by reversing the bytes in the
        // specified int value
        System.out.println("After reversing the bytes we get = " + 
        Integer.reverseBytes(a));
  
        a = "81"; // compile time error will be generated
        System.out.println(" Integral Number = " + a);
        System.out.println("After reversing the bytes we get = " + 
        Integer.reverseBytes(a));
    }
}

输出：

prog.java:9: error: incompatible types: possible lossy conversion from double to int
    int a = 37.81;
            ^
prog.java:18: error: incompatible types: String cannot be converted to int
    a = "81";
        ^
2 errors