Guava BigIntegerMath類

BigIntegerMath提供BigInteger的實用方法。

類聲明

以下是com.google.common.math.BigIntegerMath類的聲明：

@GwtCompatible(emulated=true)
public final class BigIntegerMath
? ?extends Object

 方法

繼承的方法

這個類繼承了以下類方法：java.lang.Object

BigIntegerMath 示例

使用所選擇的任何編輯器創建下面的java程序 C:/> Guava

GuavaTester.java

import java.math.BigInteger;
import java.math.RoundingMode;

import com.google.common.math.BigIntegerMath;

public class GuavaTester {

   public static void main(String args[]){
      GuavaTester tester = new GuavaTester();
      tester.testBigIntegerMath();
   }
   private void testBigIntegerMath(){
      System.out.println(BigIntegerMath.divide(BigInteger.TEN, new BigInteger("2"), RoundingMode.UNNECESSARY));
      try{
         //exception will be thrown as 100 is not completely divisible by 3 thus rounding
         // is required, and RoundingMode is set as UNNESSARY
         System.out.println(BigIntegerMath.divide(BigInteger.TEN, new BigInteger("3"), RoundingMode.UNNECESSARY));
      }catch(ArithmeticException e){
         System.out.println("Error: " + e.getMessage());
      }

      System.out.println("Log2(2): "+BigIntegerMath.log2(new BigInteger("2"), RoundingMode.HALF_EVEN));

      System.out.println("Log10(10): "+BigIntegerMath.log10(BigInteger.TEN, RoundingMode.HALF_EVEN));

      System.out.println("sqrt(100): "+BigIntegerMath.sqrt(BigInteger.TEN.multiply(BigInteger.TEN), RoundingMode.HALF_EVEN));

      System.out.println("factorial(5): "+BigIntegerMath.factorial(5));
   }
}

驗證結果

使用javac編譯器編譯如下類

C:\Guava>javac GuavaTester.java

現在運行GuavaTester看到的結果

C:\Guava>java GuavaTester

看到結果

5
Error: Rounding necessary
Log2(2): 1
Log10(10): 1
sqrt(100): 10
factorial(5): 120

 

 

 

 

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