Double.CompareTo Método
Definición
Importante
Parte de la información hace referencia a la versión preliminar del producto, que puede haberse modificado sustancialmente antes de lanzar la versión definitiva. Microsoft no otorga ninguna garantía, explícita o implícita, con respecto a la información proporcionada aquí.
Sobrecargas
| CompareTo(Double) |
Compara esta instancia con un número de punto flotante de precisión doble especificado y devuelve un entero que indica si el valor de esta instancia es mayor, menor o igual que el valor del número de punto flotante de precisión doble especificado. |
| CompareTo(Object) |
Compara esta instancia con un objeto especificado y devuelve un entero que indica si el valor de esta instancia es mayor, igual o menor que el valor del objeto especificado. |
CompareTo(Double)
Compara esta instancia con un número de punto flotante de precisión doble especificado y devuelve un entero que indica si el valor de esta instancia es mayor, menor o igual que el valor del número de punto flotante de precisión doble especificado.
public:
virtual int CompareTo(double value);public int CompareTo (double value);abstract member CompareTo : double -> int
override this.CompareTo : double -> intPublic Function CompareTo (value As Double) As IntegerParámetros
- value
- Double
Número de punto flotante de precisión doble que se va a comparar.
Devoluciones
Número con signo que indica los valores relativos de esta instancia y value.
| Valor devuelto | Descripción |
|---|---|
| Menor que cero | Esta instancia es menor que value, o bien esta instancia no es un número (NaN) y value es un número.
|
| Cero | Esta instancia es igual a value, o bien esta instancia y value no son un número (NaN), PositiveInfinity o NegativeInfinity.
|
| Mayor que cero | Esta instancia es mayor que value, o bien esta instancia es un número y value no es un número (NaN).
|
Implementaciones
Ejemplos
En el ejemplo de código siguiente se muestran versiones genéricas y no genéricas del CompareTo método para varios tipos de valor y referencia.
// This example demonstrates the two versions of the
// CompareTo method for several base types.
// The general version takes a parameter of type Object, while the specific
// version takes a type-specific parameter, such as Boolean, Int32, or Double.
using namespace System;
void Show( String^ caption, Object^ var1, Object^ var2, int resultGeneric, int resultNonGeneric )
{
String^ relation;
Console::Write( caption );
if ( resultGeneric == resultNonGeneric )
{
if ( resultGeneric < 0 )
relation = "less than";
else
if ( resultGeneric > 0 )
relation = "greater than";
else
relation = "equal to";
Console::WriteLine( "{0} is {1} {2}", var1, relation, var2 );
}
// The following condition will never occur because the generic and non-generic
// CompareTo methods are equivalent.
else
{
Console::WriteLine( "Generic CompareTo = {0}; non-generic CompareTo = {1}", resultGeneric, resultNonGeneric );
}
}
int main()
{
String^ nl = Environment::NewLine;
String^ msg = "{0}The following is the result of using the generic and non-generic{0}"
"versions of the CompareTo method for several base types:{0}";
Object^ obj; // An Object used to insure CompareTo(Object) is called.
DateTime now = DateTime::Now;
// Time span = 11 days, 22 hours, 33 minutes, 44 seconds
TimeSpan tsX = TimeSpan(11,22,33,44);
// Version = 1.2.333.4
Version^ versX = gcnew Version( "1.2.333.4" );
// Guid = CA761232-ED42-11CE-BACD-00AA0057B223
Guid guidX = Guid( "{CA761232-ED42-11CE-BACD-00AA0057B223}");
Boolean a1 = true,a2 = true;
Byte b1 = 1,b2 = 1;
Int16 c1 = -2,c2 = 2;
Int32 d1 = 3,d2 = 3;
Int64 e1 = 4,e2 = -4;
Decimal f1 = Decimal(-5.5), f2 = Decimal(5.5);
Single g1 = 6.6f,g2 = 6.6f;
Double h1 = 7.7,h2 = -7.7;
Char i1 = 'A',i2 = 'A';
String^ j1 = "abc", ^j2 = "abc";
DateTime k1 = now,k2 = now;
TimeSpan l1 = tsX,l2 = tsX;
Version^ m1 = versX, ^m2 = gcnew Version( "2.0" );
Guid n1 = guidX,n2 = guidX;
// The following types are not CLS-compliant.
SByte w1 = 8,w2 = 8;
UInt16 x1 = 9,x2 = 9;
UInt32 y1 = 10,y2 = 10;
UInt64 z1 = 11,z2 = 11;
//
Console::WriteLine( msg, nl );
try
{
Show( "Boolean: ", a1, a2, a1.CompareTo( a2 ), a1.CompareTo( a2 ) );
Show( "Byte: ", b1, b2, b1.CompareTo( b2 ), b1.CompareTo( b2 ) );
Show( "Int16: ", c1, c2, c1.CompareTo( c2 ), c1.CompareTo( c2 ) );
Show( "Int32: ", d1, d2, d1.CompareTo( d2 ), d1.CompareTo( d2 ) );
Show( "Int64: ", e1, e2, e1.CompareTo( e2 ), e1.CompareTo( e2 ) );
Show( "Decimal: ", f1, f2, f1.CompareTo( f2 ), f1.CompareTo( f2 ) );
Show( "Single: ", g1, g2, g1.CompareTo( g2 ), g1.CompareTo( g2 ) );
Show( "Double: ", h1, h2, h1.CompareTo( h2 ), h1.CompareTo( h2 ) );
Show( "Char: ", i1, i2, i1.CompareTo( i2 ), i1.CompareTo( i2 ) );
// Use an anonymous object to hide the String object.
obj = j2;
Show( "String: ", j1, j2, j1->CompareTo( j2 ), j1->CompareTo( obj ) );
Show( "DateTime:", k1, k2, k1.CompareTo( k2 ), k1.CompareTo( k2 ) );
Show( "TimeSpan: ", l1, l2, l1.CompareTo( l2 ), l1.CompareTo( l2 ) );
// Use an anonymous object to hide the Version object.
obj = m2;
Show( "Version: ", m1, m2, m1->CompareTo( m2 ), m1->CompareTo( obj ) );
Show( "Guid: ", n1, n2, n1.CompareTo( n2 ), n1.CompareTo( n2 ) );
//
Console::WriteLine( "{0}The following types are not CLS-compliant:", nl );
Show( "SByte: ", w1, w2, w1.CompareTo( w2 ), w1.CompareTo( w2 ) );
Show( "UInt16: ", x1, x2, x1.CompareTo( x2 ), x1.CompareTo( x2 ) );
Show( "UInt32: ", y1, y2, y1.CompareTo( y2 ), y1.CompareTo( y2 ) );
Show( "UInt64: ", z1, z2, z1.CompareTo( z2 ), z1.CompareTo( z2 ) );
}
catch ( Exception^ e )
{
Console::WriteLine( e );
}
}
// This example displays the following output:
//
// The following is the result of using the generic and non-generic versions of the
// CompareTo method for several base types:
//
// Boolean: True is equal to True
// Byte: 1 is equal to 1
// Int16: -2 is less than 2
// Int32: 3 is equal to 3
// Int64: 4 is greater than -4
// Decimal: -5.5 is less than 5.5
// Single: 6.6 is equal to 6.6
// Double: 7.7 is greater than -7.7
// Char: A is equal to A
// String: abc is equal to abc
// DateTime: 12/1/2003 5:37:46 PM is equal to 12/1/2003 5:37:46 PM
// TimeSpan: 11.22:33:44 is equal to 11.22:33:44
// Version: 1.2.333.4 is less than 2.0
// Guid: ca761232-ed42-11ce-bacd-00aa0057b223 is equal to ca761232-ed42-11ce-bacd-00
// aa0057b223
//
// The following types are not CLS-compliant:
// SByte: 8 is equal to 8
// UInt16: 9 is equal to 9
// UInt32: 10 is equal to 10
// UInt64: 11 is equal to 11
// This example demonstrates the generic and non-generic versions of the
// CompareTo method for several base types.
// The non-generic version takes a parameter of type Object, while the generic
// version takes a type-specific parameter, such as Boolean, Int32, or Double.
using System;
class Sample
{
public static void Main()
{
string nl = Environment.NewLine;
string msg = "{0}The following is the result of using the generic and non-generic{0}" +
"versions of the CompareTo method for several base types:{0}";
DateTime now = DateTime.Now;
// Time span = 11 days, 22 hours, 33 minutes, 44 seconds
TimeSpan tsX = new TimeSpan(11, 22, 33, 44);
// Version = 1.2.333.4
Version versX = new Version("1.2.333.4");
// Guid = CA761232-ED42-11CE-BACD-00AA0057B223
Guid guidX = new Guid("{CA761232-ED42-11CE-BACD-00AA0057B223}");
Boolean a1 = true, a2 = true;
Byte b1 = 1, b2 = 1;
Int16 c1 = -2, c2 = 2;
Int32 d1 = 3, d2 = 3;
Int64 e1 = 4, e2 = -4;
Decimal f1 = -5.5m, f2 = 5.5m;
Single g1 = 6.6f, g2 = 6.6f;
Double h1 = 7.7d, h2 = -7.7d;
Char i1 = 'A', i2 = 'A';
String j1 = "abc", j2 = "abc";
DateTime k1 = now, k2 = now;
TimeSpan l1 = tsX, l2 = tsX;
Version m1 = versX, m2 = new Version("2.0");
Guid n1 = guidX, n2 = guidX;
// The following types are not CLS-compliant.
SByte w1 = 8, w2 = 8;
UInt16 x1 = 9, x2 = 9;
UInt32 y1 = 10, y2 = 10;
UInt64 z1 = 11, z2 = 11;
//
Console.WriteLine(msg, nl);
try
{
// The second and third Show method call parameters are automatically boxed because
// the second and third Show method declaration arguments expect type Object.
Show("Boolean: ", a1, a2, a1.CompareTo(a2), a1.CompareTo((Object)a2));
Show("Byte: ", b1, b2, b1.CompareTo(b2), b1.CompareTo((Object)b2));
Show("Int16: ", c1, c2, c1.CompareTo(c2), c1.CompareTo((Object)c2));
Show("Int32: ", d1, d2, d1.CompareTo(d2), d1.CompareTo((Object)d2));
Show("Int64: ", e1, e2, e1.CompareTo(e2), e1.CompareTo((Object)e2));
Show("Decimal: ", f1, f2, f1.CompareTo(f2), f1.CompareTo((Object)f2));
Show("Single: ", g1, g2, g1.CompareTo(g2), g1.CompareTo((Object)g2));
Show("Double: ", h1, h2, h1.CompareTo(h2), h1.CompareTo((Object)h2));
Show("Char: ", i1, i2, i1.CompareTo(i2), i1.CompareTo((Object)i2));
Show("String: ", j1, j2, j1.CompareTo(j2), j1.CompareTo((Object)j2));
Show("DateTime: ", k1, k2, k1.CompareTo(k2), k1.CompareTo((Object)k2));
Show("TimeSpan: ", l1, l2, l1.CompareTo(l2), l1.CompareTo((Object)l2));
Show("Version: ", m1, m2, m1.CompareTo(m2), m1.CompareTo((Object)m2));
Show("Guid: ", n1, n2, n1.CompareTo(n2), n1.CompareTo((Object)n2));
//
Console.WriteLine("{0}The following types are not CLS-compliant:", nl);
Show("SByte: ", w1, w2, w1.CompareTo(w2), w1.CompareTo((Object)w2));
Show("UInt16: ", x1, x2, x1.CompareTo(x2), x1.CompareTo((Object)x2));
Show("UInt32: ", y1, y2, y1.CompareTo(y2), y1.CompareTo((Object)y2));
Show("UInt64: ", z1, z2, z1.CompareTo(z2), z1.CompareTo((Object)z2));
}
catch (Exception e)
{
Console.WriteLine(e);
}
}
public static void Show(string caption, Object var1, Object var2,
int resultGeneric, int resultNonGeneric)
{
string relation;
Console.Write(caption);
if (resultGeneric == resultNonGeneric)
{
if (resultGeneric < 0) relation = "less than";
else if (resultGeneric > 0) relation = "greater than";
else relation = "equal to";
Console.WriteLine("{0} is {1} {2}", var1, relation, var2);
}
// The following condition will never occur because the generic and non-generic
// CompareTo methods are equivalent.
else
{
Console.WriteLine("Generic CompareTo = {0}; non-generic CompareTo = {1}",
resultGeneric, resultNonGeneric);
}
}
}
/*
This example produces the following results:
The following is the result of using the generic and non-generic versions of the
CompareTo method for several base types:
Boolean: True is equal to True
Byte: 1 is equal to 1
Int16: -2 is less than 2
Int32: 3 is equal to 3
Int64: 4 is greater than -4
Decimal: -5.5 is less than 5.5
Single: 6.6 is equal to 6.6
Double: 7.7 is greater than -7.7
Char: A is equal to A
String: abc is equal to abc
DateTime: 12/1/2003 5:37:46 PM is equal to 12/1/2003 5:37:46 PM
TimeSpan: 11.22:33:44 is equal to 11.22:33:44
Version: 1.2.333.4 is less than 2.0
Guid: ca761232-ed42-11ce-bacd-00aa0057b223 is equal to ca761232-ed42-11ce-bacd-00
aa0057b223
The following types are not CLS-compliant:
SByte: 8 is equal to 8
UInt16: 9 is equal to 9
UInt32: 10 is equal to 10
UInt64: 11 is equal to 11
*/
' This example demonstrates the generic and non-generic versions of the
' CompareTo method for several base types.
' The non-generic version takes a parameter of type Object, while the generic
' version takes a type-specific parameter, such as Boolean, Int32, or Double.
Class Sample
Public Shared Sub Main()
Dim nl As String = Environment.NewLine
Dim msg As String = _
"{0}The following is the result of using the generic and non-generic{0}" & _
"versions of the CompareTo method for several base types:{0}"
Dim now As DateTime = DateTime.Now
' Time span = 11 days, 22 hours, 33 minutes, 44 seconds
Dim tsX As New TimeSpan(11, 22, 33, 44)
' Version = 1.2.333.4
Dim versX As New Version("1.2.333.4")
' Guid = CA761232-ED42-11CE-BACD-00AA0057B223
Dim guidX As New Guid("{CA761232-ED42-11CE-BACD-00AA0057B223}")
Dim a1 As [Boolean] = True, a2 As [Boolean] = True
Dim b1 As [Byte] = 1, b2 As [Byte] = 1
Dim c1 As Int16 = -2, c2 As Int16 = 2
Dim d1 As Int32 = 3, d2 As Int32 = 3
Dim e1 As Int64 = 4, e2 As Int64 = -4
Dim f1 As [Decimal] = -5.5D, f2 As [Decimal] = 5.5D
Dim g1 As [Single] = 6.6F, g2 As [Single] = 6.6F
Dim h1 As [Double] = 7.7, h2 As [Double] = -7.7
Dim i1 As [Char] = "A"c, i2 As [Char] = "A"c
Dim j1 As String = "abc", j2 As String = "abc"
Dim k1 As DateTime = now, k2 As DateTime = now
Dim l1 As TimeSpan = tsX, l2 As TimeSpan = tsX
Dim m1 As Version = versX, m2 As New Version("2.0")
Dim n1 As Guid = guidX, n2 As Guid = guidX
' The following types are not CLS-compliant.
' SByte, UInt16, UInt32, UInt64
Console.WriteLine(msg, nl)
Try
' The second and third Show method call parameters are automatically boxed because
' the second and third Show method declaration arguments expect type Object.
Show("Boolean: ", a1, a2, a1.CompareTo(a2), a1.CompareTo(CObj(a2)))
Show("Byte: ", b1, b2, b1.CompareTo(b2), b1.CompareTo(CObj(b2)))
Show("Int16: ", c1, c2, c1.CompareTo(c2), c1.CompareTo(CObj(c2)))
Show("Int32: ", d1, d2, d1.CompareTo(d2), d1.CompareTo(CObj(d2)))
Show("Int64: ", e1, e2, e1.CompareTo(e2), e1.CompareTo(CObj(e2)))
Show("Decimal: ", f1, f2, f1.CompareTo(f2), f1.CompareTo(CObj(f2)))
Show("Single: ", g1, g2, g1.CompareTo(g2), g1.CompareTo(CObj(g2)))
Show("Double: ", h1, h2, h1.CompareTo(h2), h1.CompareTo(CObj(h2)))
Show("Char: ", i1, i2, i1.CompareTo(i2), i1.CompareTo(CObj(i2)))
Show("String: ", j1, j2, j1.CompareTo(j2), j1.CompareTo(CObj(j2)))
Show("DateTime: ", k1, k2, k1.CompareTo(k2), k1.CompareTo(CObj(k2)))
Show("TimeSpan: ", l1, l2, l1.CompareTo(l2), l1.CompareTo(CObj(l2)))
Show("Version: ", m1, m2, m1.CompareTo(m2), m1.CompareTo(CObj(m2)))
Show("Guid: ", n1, n2, n1.CompareTo(n2), n1.CompareTo(CObj(n2)))
'
Console.WriteLine("{0}The following types are not CLS-compliant:", nl)
Console.WriteLine("SByte, UInt16, UInt32, UInt64")
Catch e As Exception
Console.WriteLine(e)
End Try
End Sub
Public Shared Sub Show(caption As String, var1 As [Object], var2 As [Object], _
resultGeneric As Integer, resultNonGeneric As Integer)
Dim relation As String
Console.Write(caption)
If resultGeneric = resultNonGeneric Then
If resultGeneric < 0 Then
relation = "less than"
ElseIf resultGeneric > 0 Then
relation = "greater than"
Else
relation = "equal to"
End If
Console.WriteLine("{0} is {1} {2}", var1, relation, var2)
' The following condition will never occur because the generic and non-generic
' CompareTo methods are equivalent.
Else
Console.WriteLine("Generic CompareTo = {0}; non-generic CompareTo = {1}", _
resultGeneric, resultNonGeneric)
End If
End Sub
End Class
'
'This example produces the following results:
'
'The following is the result of using the generic and non-generic versions of the
'CompareTo method for several base types:
'
'Boolean: True is equal to True
'Byte: 1 is equal to 1
'Int16: -2 is less than 2
'Int32: 3 is equal to 3
'Int64: 4 is greater than -4
'Decimal: -5.5 is less than 5.5
'Single: 6.6 is equal to 6.6
'Double: 7.7 is greater than -7.7
'Char: A is equal to A
'String: abc is equal to abc
'DateTime: 12/1/2003 5:37:46 PM is equal to 12/1/2003 5:37:46 PM
'TimeSpan: 11.22:33:44 is equal to 11.22:33:44
'Version: 1.2.333.4 is less than 2.0
'Guid: ca761232-ed42-11ce-bacd-00aa0057b223 is equal to ca761232-ed42-11ce-bacd-00
'aa0057b223
'
'The following types are not CLS-compliant:
'SByte, UInt16, UInt32, UInt64
'
Comentarios
Los valores deben ser idénticos para considerarse iguales. Especialmente cuando los valores de punto flotante dependen de varias operaciones matemáticas, es habitual que pierdan precisión y que sus valores sean casi idénticos, excepto por sus dígitos menos significativos. Por este motivo, el valor devuelto del CompareTo método en ocasiones puede parecer sorprendente. Por ejemplo, la multiplicación por un valor determinado seguido de la división por el mismo valor debe generar el valor original. Sin embargo, en el ejemplo siguiente, el valor calculado resulta ser mayor que el valor original. Mostrar todos los dígitos significativos de los dos valores mediante la cadena de formato numérico estándar "R" indica que el valor calculado difiere del valor original en sus dígitos menos significativos. Para obtener información sobre cómo controlar estas comparaciones, vea la sección Comentarios del Equals(Double) método .
using System;
public class Example
{
public static void Main()
{
double value1 = 6.185;
double value2 = value1 * .1 / .1;
Console.WriteLine("Comparing {0} and {1}: {2}\n",
value1, value2, value1.CompareTo(value2));
Console.WriteLine("Comparing {0:R} and {1:R}: {2}",
value1, value2, value1.CompareTo(value2));
}
}
// The example displays the following output:
// Comparing 6.185 and 6.185: -1
//
// Comparing 6.185 and 6.1850000000000005: -1
let value1 = 6.185
let value2 = value1 * 0.1 / 0.1
printfn $"Comparing {value1} and {value2}: {value1.CompareTo value2}\n"
printfn $"Comparing {value1:R} and {value2:R}: {value1.CompareTo value2}"
// The example displays the following output:
// Comparing 6.185 and 6.185: -1
//
// Comparing 6.185 and 6.1850000000000005: -1
Module Example
Public Sub Main()
Dim value1 As Double = 6.185
Dim value2 As Double = value1 * .1 / .1
Console.WriteLine("Comparing {0} and {1}: {2}",
value1, value2, value1.CompareTo(value2))
Console.WriteLine()
Console.WriteLine("Comparing {0:R} and {1:R}: {2}",
value1, value2, value1.CompareTo(value2))
End Sub
End Module
' The example displays the following output:
' Comparing 6.185 and 6.185: -1
'
' Comparing 6.185 and 6.1850000000000005: -1
Este método implementa la System.IComparable<T> interfaz y funciona ligeramente mejor que el Double.CompareTo método porque no tiene que convertir el value parámetro en un objeto .
Tenga en cuenta que, aunque un objeto cuyo valor no se NaN considera igual a otro objeto cuyo valor es NaN (incluso en sí mismo), la IComparable<T> interfaz requiere que A.CompareTo(A) devuelva cero.
conversiones de ampliación
En función del lenguaje de programación, es posible codificar un CompareTo método en el que el tipo de parámetro tenga menos bits (es más estrecho) que el tipo de instancia. Esto es posible porque algunos lenguajes de programación realizan una conversión de ampliación implícita que representa el parámetro como un tipo con tantos bits como la instancia.
Por ejemplo, supongamos que el tipo de instancia es Double y el tipo de parámetro es Int32. El compilador de C# Microsoft genera instrucciones para representar el valor del parámetro como un Double objeto y, a continuación, genera un Double.CompareTo(Double) método que compara los valores de la instancia y la representación ampliada del parámetro.
Consulte la documentación del lenguaje de programación para determinar si su compilador realiza conversiones de ampliación implícitas de tipos numéricos. Para obtener más información, vea el tema Tablas de conversión de tipos.
Precisión en comparaciones
La precisión de los números de punto flotante más allá de la precisión documentada es específica de la implementación y la versión de .NET Framework. Por lo tanto, una comparación de dos números concretos podría cambiar entre las versiones de .NET Framework porque la precisión de la representación interna de los números podría cambiar.
Consulte también
Se aplica a
CompareTo(Object)
Compara esta instancia con un objeto especificado y devuelve un entero que indica si el valor de esta instancia es mayor, igual o menor que el valor del objeto especificado.
public:
virtual int CompareTo(System::Object ^ value);public int CompareTo (object? value);public int CompareTo (object value);abstract member CompareTo : obj -> int
override this.CompareTo : obj -> intPublic Function CompareTo (value As Object) As IntegerParámetros
- value
- Object
Objeto que se va a comparar o null.
Devoluciones
Número con signo que indica los valores relativos de esta instancia y value.
| Valor | Descripción |
|---|---|
| Un entero negativo | Esta instancia es menor que value, o bien esta instancia no es un número (NaN) y value es un número.
|
| Cero | Esta instancia es igual a value, o bien esta instancia y value son Double.NaN, PositiveInfinity o NegativeInfinity |
| Un entero positivo. | Esta instancia es mayor que value, O BIEN esta instancia es un número y value no es un número (NaN), O BIEN value es null. |
Implementaciones
Excepciones
value no es un Double.
Ejemplos
En el ejemplo de código siguiente se muestra el uso de CompareTo en el contexto de Double.
obj1 = (Double)450;
if ( a.CompareTo( obj1 ) < 0 )
{
Console::WriteLine( "{0} is less than {1}.", a, obj1 );
}
if ( a.CompareTo( obj1 ) > 0 )
{
Console::WriteLine( "{0} is greater than {1}.", a, obj1 );
}
if ( a.CompareTo( obj1 ) == 0 )
{
Console::WriteLine( "{0} equals {1}.", a, obj1 );
}
obj1 = (Double)450;
if (a.CompareTo(obj1) < 0)
Console.WriteLine("{0} is less than {1}.", a.ToString(), obj1.ToString());
if (a.CompareTo(obj1) > 0)
Console.WriteLine("{0} is greater than {1}.", a.ToString(), obj1.ToString());
if (a.CompareTo(obj1) == 0)
Console.WriteLine("{0} equals {1}.", a.ToString(), obj1.ToString());
let obj1 = double 450 |> box
if a.CompareTo obj1 < 0 then
printfn $"{a} is less than {obj1}."
if a.CompareTo obj1 > 0 then
printfn $"{a} is greater than {obj1}."
if a.CompareTo obj1 = 0 then
printfn $"{a} equals {obj1}."
Obj1 = CType(450, Double)
If A.CompareTo(Obj1) < 0 Then
Console.WriteLine(A.ToString() + " is less than " + Obj1.ToString() + ".")
End If
If (A.CompareTo(Obj1) > 0) Then
Console.WriteLine(A.ToString() + " is greater than " + Obj1.ToString() + ".")
End If
If (A.CompareTo(Obj1) = 0) Then
Console.WriteLine(A.ToString() + " equals " + Obj1.ToString() + ".")
End If
Comentarios
El value parámetro debe ser null o una instancia de Double; de lo contrario, se produce una excepción. Cualquier instancia de Double, independientemente de su valor, se considera mayor que null.
Los valores deben ser idénticos para considerarse iguales. Especialmente cuando los valores de punto flotante dependen de varias operaciones matemáticas, es habitual que pierdan precisión y que sus valores sean casi idénticos, excepto por sus dígitos menos significativos. Por este motivo, el valor devuelto del CompareTo método en ocasiones puede parecer sorprendente. Por ejemplo, la multiplicación por un valor determinado seguido de la división por el mismo valor debe generar el valor original. Sin embargo, en el ejemplo siguiente, el valor calculado resulta ser mayor que el valor original. Mostrar todos los dígitos significativos de los dos valores mediante la cadena de formato numérico estándar "R" indica que el valor calculado difiere del valor original en sus dígitos menos significativos. Para obtener información sobre cómo controlar estas comparaciones, vea la sección Comentarios del Equals(Double) método .
using System;
public class Example
{
public static void Main()
{
double value1 = 6.185;
object value2 = value1 * .1 / .1;
Console.WriteLine("Comparing {0} and {1}: {2}\n",
value1, value2, value1.CompareTo(value2));
Console.WriteLine("Comparing {0:R} and {1:R}: {2}",
value1, value2, value1.CompareTo(value2));
}
}
// The example displays the following output:
// Comparing 6.185 and 6.185: -1
//
// Comparing 6.185 and 6.1850000000000005: -1
let value1 = 6.185
let value2 = value1 * 0.1 / 0.1 |> box
printfn $"Comparing {value1} and {value2}: {value1.CompareTo value2}\n"
printfn $"Comparing {value1:R} and {value2:R}: {value1.CompareTo value2}"
// The example displays the following output:
// Comparing 6.185 and 6.185: -1
//
// Comparing 6.185 and 6.1850000000000005: -1
Module Example
Public Sub Main()
Dim value1 As Double = 6.185
Dim value2 As Object = value1 * .1 / .1
Console.WriteLine("Comparing {0} and {1}: {2}",
value1, value2, value1.CompareTo(value2))
Console.WriteLine()
Console.WriteLine("Comparing {0:R} and {1:R}: {2}",
value1, value2, value1.CompareTo(value2))
End Sub
End Module
' The example displays the following output:
' Comparing 6.185 and 6.185: -1
'
' Comparing 6.185 and 6.1850000000000005: -1
Este método se implementa para admitir la IComparable interfaz . Tenga en cuenta que, aunque NaN no se considera que es igual a otro NaN (incluso en sí mismo), la IComparable interfaz requiere que A.CompareTo(A) devuelva cero.
Precisión en comparaciones
La precisión de los números de punto flotante más allá de la precisión documentada es específica de la implementación y la versión de .NET Framework. Por lo tanto, una comparación de dos números concretos podría cambiar entre las versiones de .NET Framework porque la precisión de la representación interna de los números podría cambiar.