BigInteger类testBit()方法 (BigInteger Class testBit() method)

• testBit() method is available in java.math package.

  testBit()方法在java.math包中可用。

• testBit() method is used to convert this BigInteger to a byte [] that holds 2's complement denotation of this BigInteger and the array capacity is enough to represent this BigInteger with one extra bit for the sign.

  testBit()方法用于将该BigInteger转换为一个字节[]，该字节持有此BigInteger的2的补码表示，并且数组容量足以用一个额外的符号表示此BigInteger。

• testBit() method is a non-static method, it is accessible with the class object only and if we try to access the method with the class name then we will get an error.

  testBit()方法是一个非静态方法，只能通过类对象访问，如果尝试使用类名称访问该方法，则会收到错误消息。

• testBit() method does not throw an exception at the time of converting this object to a byte array.

  在将此对象转换为字节数组时， testBit()方法不会引发异常。

Syntax:

句法：

    public byte[] toByteArray();

Parameter(s):

参数：

• None

  没有

Return value:

返回值：

The return type of this method is byte[], it represents this BigInteger in terms of 2’s complement in byte array.

此方法的返回类型为byte [] ，它以字节数组中2的补码形式表示此BigInteger。

Example:

例：

// Java program to demonstrate the example
// of byte[] toByteArray() method of BigInteger
import java.math.*;
import java.util.*;
public class ToByteArrayOfBI {public static void main(String args[]) {// Initializes a variable str
String str = "145";
// Initializes a BigInteger object
BigInteger b_int = new BigInteger(str);
// returns the convert this BigInteger
// into a byte[] that contains 2's complement of
// this BigInteger
byte[] b_arr = b_int.toByteArray();
for (int i = 0; i < b_arr.length; ++i)
System.out.println("b_int.toByteArray(): " + b_arr[i] + " ");
}
}

Output

输出量

b_int.toByteArray(): 0
b_int.toByteArray(): -111

翻译自: https://www.includehelp.com/java/biginteger-tobytearray-method-with-example.aspx