BigInteger类的bitCount()方法 (BigInteger Class bitCount() method)

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

  bitCount()方法在java.math包中可用。

• bitCount() method is used to count the number of bits in 2’s complement denotation of this BigInteger.

  bitCount()方法用于计算此BigInteger的2的补码表示形式中的位数。

• bitCount() 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.

  bitCount()方法是一种非静态方法，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。

• bitCount() method does not throw an exception at the time of counting bits.

  在对位进行计数时， bitCount()方法不会引发异常。

Syntax:

句法：

    public int bitCount();

Parameter(s):

参数：

• None

  没有

Return value:

返回值：

The return type of this method is BigInteger, it returns number of bits in 2's complement denotation of this BigInteger.

此方法的返回类型为BigInteger ，它返回此BigInteger的2的补码表示形式的位数。

Example:

例：

// Java program to demonstrate the example
// of int bitCount() method of BigInteger
import java.math.*;
public class BitCountOfBI {public static void main(String args[]) {// Initialize two variables str1 and str2
String str1 = "10";
String str2 = "-4";
// Initialize two BigInteger objects
BigInteger b_int1 = new BigInteger(str1);
BigInteger b_int2 = new BigInteger(str2);
System.out.println("b_int1: " + b_int1);
System.out.println("b_int2: " + b_int2);
// returns the number of bits in 2's complement
// representation of this BigInteger b_dec1
int bit_count = b_int1.bitCount();
System.out.println("b_int1.bitCount(): " + bit_count);
// returns the number of bits in 2's complement
// representation of this BigInteger b_dec2 and it
// may differ from its sign bit
bit_count = b_int2.bitCount();
System.out.println("b_int2.bitCount(): " + bit_count);
}
}

Output

输出量

b_int1: 10
b_int2: -4
b_int1.bitCount(): 2
b_int2.bitCount(): 2

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