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Double Structure

Represents a double-precision floating point number.

For a list of all members of this type, see Double Members.

System.Object
   System.ValueType
      System.Double

[Visual Basic]
<Serializable>
Public Structure Double
   Implements IComparable, IFormattable, IConvertible
[C#]
[Serializable]
public struct Double : IComparable, IFormattable, IConvertible
[C++]
[Serializable]
public __value struct Double : public IComparable, IFormattable,
   IConvertible

[JScript] In JScript, you can use the structures in the .NET Framework, but you cannot define your own.

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Remarks

The Double value type represents a double-precision 64-bit number with values ranging from negative 1.79769313486232e308 to positive 1.79769313486232e308, as well as positive or negative zero, PositiveInfinity, NegativeInfinity, and Not-a-Number (NaN).

Double complies with the IEC 60559:1989 (IEEE 754) standard for binary floating-point arithmetic.

Double provides methods to compare instances of this type, convert the value of an instance to its string representation, and convert the string representation of a number to an instance of this type.

For information about how format specification codes control the string representation of value types, see Formatting Overview.

This type implements interfaces IComparable, IFormattable, and IConvertible. Use the Convert class for conversions instead of this type's explicit interface member implementation of IConvertible.

When performing binary operations, if one of the operands is a Double, then the other operand is required to be an integral type or a floating-point type (Double or Single). Prior to performing the operation, if the other operand is not a Double, it is converted to Double, and the operation is performed using at least Double range and precision. If the operation produces a numeric result, the type of the result is Double.

The floating-point operators, including the assignment operators, do not throw exceptions. Instead, in exceptional situations, the result of a floating-point operation is zero, infinity, or NaN, as described below:

  • If the result of a floating-point operation is too small for the destination format, the result of the operation is zero.
  • If the magnitude of the result of a floating-point operation is too large for the destination format, the result of the operation is PositiveInfinity or NegativeInfinity, as appropriate for the sign of the result.
  • If a floating-point operation is invalid, the result of the operation is NaN.
  • If one or both operands of a floating-point operation are NaN, the result of the operation is NaN.

Example

The following code sample illustrates the use of Double:

[Visual Basic] 
' Temperature class stores the value as Double
' and delegates most of the functionality 
' to the Double implementation.
Public Class Temperature
    Implements IComparable, IFormattable

    Public Overloads Function CompareTo(ByVal obj As Object) As Integer _
        Implements IComparable.CompareTo

        If TypeOf obj Is Temperature Then
            Dim temp As Temperature = CType(obj, Temperature)

            Return m_value.CompareTo(temp.m_value)
        End If

        Throw New ArgumentException("object is not a Temperature")
    End Function

    Public Overloads Function ToString(ByVal format As String, ByVal provider As IFormatProvider) As String _
        Implements IFormattable.ToString

        If Not (format Is Nothing) Then
            If format.Equals("F") Then
                Return [String].Format("{0}'F", Me.Value.ToString())
            End If
            If format.Equals("C") Then
                Return [String].Format("{0}'C", Me.Celsius.ToString())
            End If
        End If

        Return m_value.ToString(format, provider)
    End Function

    ' Parses the temperature from a string in form
    ' [ws][sign]digits['F|'C][ws]
    Public Shared Function Parse(ByVal s As String, ByVal styles As NumberStyles, ByVal provider As IFormatProvider) As Temperature
        Dim temp As New Temperature()

        If s.TrimEnd(Nothing).EndsWith("'F") Then
            temp.Value = Double.Parse(s.Remove(s.LastIndexOf("'"c), 2), styles, provider)
        Else
            If s.TrimEnd(Nothing).EndsWith("'C") Then
                temp.Celsius = Double.Parse(s.Remove(s.LastIndexOf("'"c), 2), styles, provider)
            Else
                temp.Value = Double.Parse(s, styles, provider)
            End If
        End If
        Return temp
    End Function

    ' The value holder
    Protected m_value As Double

    Public Property Value() As Double
        Get
            Return m_value
        End Get
        Set(ByVal Value As Double)
            m_value = Value
        End Set
    End Property

    Public Property Celsius() As Double
        Get
            Return (m_value - 32) / 1.8
        End Get
        Set(ByVal Value As Double)
            m_value = Value * 1.8 + 32
        End Set
    End Property
End Class

[C#] 
/// <summary>
/// Temperature class stores the value as Double
/// and delegates most of the functionality 
/// to the Double implementation.
/// </summary>
public class Temperature : IComparable, IFormattable {
    /// <summary>
    /// IComparable.CompareTo implementation.
    /// </summary>
    public int CompareTo(object obj) {
        if(obj is Temperature) {
            Temperature temp = (Temperature) obj;

            return m_value.CompareTo(temp.m_value);
        }
        
        throw new ArgumentException("object is not a Temperature");    
    }

    /// <summary>
    /// IFormattable.ToString implementation.
    /// </summary>
    public string ToString(string format, IFormatProvider provider) {
        if( format != null ) {
            if( format.Equals("F") ) {
                return String.Format("{0}'F", this.Value.ToString());
            }
            if( format.Equals("C") ) {
                return String.Format("{0}'C", this.Celsius.ToString());
            }
        }

        return m_value.ToString(format, provider);
    }

    /// <summary>
    /// Parses the temperature from a string in form
    /// [ws][sign]digits['F|'C][ws]
    /// </summary>
    public static Temperature Parse(string s, NumberStyles styles, IFormatProvider provider) {
        Temperature temp = new Temperature();

        if( s.TrimEnd(null).EndsWith("'F") ) {
            temp.Value = Double.Parse( s.Remove(s.LastIndexOf('\''), 2), styles, provider);
        }
        else if( s.TrimEnd(null).EndsWith("'C") ) {
            temp.Celsius = Double.Parse( s.Remove(s.LastIndexOf('\''), 2), styles, provider);
        }
        else {
            temp.Value = Double.Parse(s, styles, provider);
        }

        return temp;
    }

    // The value holder
    protected double m_value;

    public double Value {
        get {
            return m_value;
        }
        set {
            m_value = value;
        }
    }

    public double Celsius {
        get {
            return (m_value-32.0)/1.8;
        }
        set {
            m_value = 1.8*value+32.0;
        }
    }
}

[C++] 
/// <summary>
/// Temperature class stores the value as Double
/// and delegates most of the functionality 
/// to the Double implementation.
/// </summary>
public __gc class Temperature : public IComparable, public IFormattable {
/// <summary>
/// IComparable.CompareTo implementation.
/// </summary>
public:
int CompareTo(Object* obj) {
   if(dynamic_cast<Temperature*>(obj)) {
      Temperature* temp = dynamic_cast<Temperature*> (obj);

      return m_value.CompareTo(__box(temp->m_value));
   }

   throw new ArgumentException(S"object is not a Temperature");    
}

/// <summary>
/// IFormattable.ToString implementation.
/// </summary>
String* ToString(String* format, IFormatProvider* provider) {
   if( format != 0 ) {
      if( format->Equals(S"F") ) {
         return String::Format(S"{0}'F", this->Value.ToString());
      }
      if( format->Equals(S"C") ) {
         return String::Format(S"{0}'C", this->Celsius.ToString());
      }
   }

   return m_value.ToString(format, provider);
}

/// <summary>
/// Parses the temperature from a string in form
/// [ws][sign]digits['F|'C][ws]
/// </summary>
static Temperature* Parse(String* s, NumberStyles styles, IFormatProvider* provider) {
   Temperature* temp = new Temperature();

   if( s->TrimEnd(0)->EndsWith(S"'F") ) {
      temp->Value = Double::Parse( s->Remove(s->LastIndexOf('\''), 2), styles, provider);
   }
   else if( s->TrimEnd(0)->EndsWith(S"'C") ) {
      temp->Celsius = Double::Parse( s->Remove(s->LastIndexOf('\''), 2), styles, provider);
   }
   else {
      temp->Value = Double::Parse(s, styles, provider);
   }

   return temp;
}

// The value holder
protected:
double m_value;

public:
__property double get_Value() {
   return m_value;
}
__property void set_Value( double value ) {
   m_value = value;
}

__property double get_Celsius() {
   return (m_value-32.0)/1.8;
}
__property void set_Celsius( double value ) {
   m_value = 1.8*value+32.0;
}

};

[JScript] 
/// <summary>
/// Temperature class stores the value as Double
/// and delegates most of the functionality 
/// to the Double implementation.
/// </summary>
public class Temperature implements IComparable, IFormattable {
    /// <summary>
    /// IComparable.CompareTo implementation.
    /// </summary>
    public function CompareTo(obj) : int{
        if(obj.GetType() == Temperature) {
            var temp : Temperature = Temperature(obj);

            return m_value.CompareTo(temp.m_value);
        }
        
        throw new ArgumentException("object is not a Temperature");    
    }

    /// <summary>
    /// IFormattable.ToString implementation.
    /// </summary>
    public function ToString(format : String, provider : IFormatProvider) : String {
        if( format != null ) {
            if( format.Equals("F") ) {
                return String.Format("{0}'F", this.Value.ToString());
            }
            if( format.Equals("C") ) {
                return String.Format("{0}'C", this.Celsius.ToString());
            }
        }

        return m_value.ToString(format, provider);
    }

    /// <summary>
    /// Parses the temperature from a string in form
    /// [ws][sign]digits['F|'C][ws]
    /// </summary>
    public static function Parse(s : String, styles : NumberStyles, provider : IFormatProvider) : Temperature{
        var temp : Temperature = new Temperature();

        if( s.TrimEnd(null).EndsWith("'F") ) {
            temp.Value = Double.Parse( s.Remove(s.LastIndexOf('\''), 2), styles, provider);
        }
        else if( s.TrimEnd(null).EndsWith("'C") ) {
            temp.Celsius = Double.Parse( s.Remove(s.LastIndexOf('\''), 2), styles, provider);
        }
        else {
            temp.Value = Double.Parse(s, styles, provider);
        }

        return temp;
    }

    // The value holder
    protected var m_value : double;

    public function get Value() : double{
        return m_value;
    }
    
            public function set Value(value : double) {
        m_value = value;
    }

    public function get Celsius() : double {
        return (m_value-32.0)/1.8;
            }
            
            public function set Celsius(value : double) {
        m_value = 1.8*value+32.0;
    }
}

Requirements

Namespace: System

Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family, .NET Compact Framework

Assembly: Mscorlib (in Mscorlib.dll)

See Also

Double Members | System Namespace

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