BigInteger.Abs(BigInteger) 方法

定义

获取 BigInteger 对象的绝对值。Gets the absolute value of a BigInteger object.

public:
 static System::Numerics::BigInteger Abs(System::Numerics::BigInteger value);
public static System.Numerics.BigInteger Abs (System.Numerics.BigInteger value);
static member Abs : System.Numerics.BigInteger -> System.Numerics.BigInteger
Public Shared Function Abs (value As BigInteger) As BigInteger

参数

value
BigInteger

数词。A number.

返回

value 的绝对值。The absolute value of value.

示例

下面的示例使用 Abs 方法,将 BigInteger 值从两个补数表示形式转换为签名和数量级表示形式,然后将其序列化到文件中。The following example uses the Abs method to convert a BigInteger value from two's complement representation to sign-and-magnitude representation before serializing it to a file. 然后,将对文件中的数据进行反序列化并将其分配给新的 BigInteger 对象。Data in the file is then deserialized and assigned to a new BigInteger object.

using System;
using System.IO;
using System.Numerics;
using System.Runtime.Serialization.Formatters.Binary;

[Serializable] public struct SignAndMagnitude
{
   public int Sign; 
   public byte[] Bytes;
}

public class Example
{
   public static void Main()
   {
      FileStream fs;
      BinaryFormatter formatter = new BinaryFormatter();

      BigInteger number = BigInteger.Pow(Int32.MaxValue, 20) * BigInteger.MinusOne;
      Console.WriteLine("The original value is {0}.", number);
      SignAndMagnitude sm = new SignAndMagnitude();
      sm.Sign = number.Sign;
      sm.Bytes = BigInteger.Abs(number).ToByteArray();
      
      // Serialize SignAndMagnitude value.
      fs = new FileStream(@".\data.bin", FileMode.Create);
      formatter.Serialize(fs, sm);
      fs.Close();
      
      // Deserialize SignAndMagnitude value.
      fs = new FileStream(@".\data.bin", FileMode.Open);
      SignAndMagnitude smRestored = (SignAndMagnitude) formatter.Deserialize(fs);
      fs.Close();
      BigInteger restoredNumber = new BigInteger(smRestored.Bytes); 
      restoredNumber *= sm.Sign; 
      Console.WriteLine("The deserialized value is {0}.", restoredNumber);      
   }
}
// The example displays the following output:
//    The original value is -4.3510823966323432743748744058E+186.
//    The deserialized value is -4.3510823966323432743748744058E+186.
Imports System.IO
Imports System.Numerics
Imports System.Runtime.Serialization.Formatters.Binary

<Serializable> Public Structure SignAndMagnitude
   Dim Sign As Integer
   Dim Bytes() As Byte
End Structure

Module Example
   Public Sub Main()
      Dim fs As FileStream
      Dim formatter As New BinaryFormatter()

      Dim number As BigInteger = BigInteger.Pow(Int32.MaxValue, 20) * BigInteger.MinusOne
      Console.WriteLine("The original value is {0}.", number)
      Dim sm As New SignAndMagnitude()
      sm.Sign = number.Sign
      sm.Bytes = BigInteger.Abs(number).ToByteArray()
      
      ' Serialize SignAndMagnitude value.
      fs = New FileStream(".\data.bin", FileMode.Create)
      formatter.Serialize(fs, sm)
      fs.Close()
      
      ' Deserialize SignAndMagnitude value.
      fs = New FileStream(".\data.bin", FileMode.Open)
      Dim smRestored As SignAndMagnitude = DirectCast(formatter.Deserialize(fs), SignAndMagnitude)
      fs.Close()
      Dim restoredNumber As New BigInteger(smRestored.Bytes) 
      restoredNumber *= sm.Sign 
      Console.WriteLine("The deserialized value is {0}.", restoredNumber)      
   End Sub
End Module
' The example displays the following output:
'    The original value is -4.3510823966323432743748744058E+186.
'    The deserialized value is -4.3510823966323432743748744058E+186.

注解

数字的绝对值是没有符号的数字,如下表所示。The absolute value of a number is that number without its sign, as shown in the following table.

value 参数value parameter 返回值Return value
value > = 0value >= 0 value
value < 0value < 0 value * -1value * -1

Abs 方法等效于基元数值类型的 Math.Abs 方法。The Abs method is equivalent to the Math.Abs method for the primitive numeric types.

适用于

另请参阅