Decimal.Equals 方法
定义
重要
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返回一个值,该值指示 Decimal 的两个实例是否表示相同的值。
重载
Equals(Decimal, Decimal) |
返回一个值,该值指示两个指定的 Decimal 实例是否表示相同的值。 |
Equals(Decimal) |
返回一个值,该值指示此实例和指定的 Decimal 对象是否表示相同的值。 |
Equals(Object) |
返回一个值,该值指示此实例和指定的 Object 是否表示相同的类型和值。 |
Equals(Decimal, Decimal)
- Source:
- Decimal.cs
- Source:
- Decimal.cs
- Source:
- Decimal.cs
返回一个值,该值指示两个指定的 Decimal 实例是否表示相同的值。
public:
static bool Equals(System::Decimal d1, System::Decimal d2);
public static bool Equals (decimal d1, decimal d2);
static member Equals : decimal * decimal -> bool
Public Shared Function Equals (d1 As Decimal, d2 As Decimal) As Boolean
参数
- d1
- Decimal
要比较的第一个值。
- d2
- Decimal
要比较的第二个值。
返回
如果 d1
和 d2
相等,则 true
;否则,false
。
示例
下面的代码示例使用静态 Equals
方法将多个 Decimal
值与引用 Decimal
值进行比较。
// Example of the Decimal::Compare and static Decimal::Equals methods.
using namespace System;
const __wchar_t * protoFmt = L"{0,-45}{1}";
// Compare Decimal parameters, and display them with the results.
void CompareDecimals( Decimal Left, Decimal Right, String^ RightText )
{
String^ dataFmt = gcnew String( protoFmt );
Console::WriteLine();
Console::WriteLine( dataFmt, String::Concat( "Right: ", RightText ), Right );
Console::WriteLine( dataFmt, "Decimal::Equals( Left, Right )", Decimal::Equals( Left, Right ) );
Console::WriteLine( dataFmt, "Decimal::Compare( Left, Right )", Decimal::Compare( Left, Right ) );
}
int main()
{
Console::WriteLine( "This example of the Decimal::Equals( Decimal, Decimal "
") and \nDecimal::Compare( Decimal, Decimal ) "
"methods generates the \nfollowing output. It creates "
"several different Decimal \nvalues and compares them "
"with the following reference value.\n" );
// Create a reference Decimal value.
Decimal Left = Decimal(123.456);
Console::WriteLine( gcnew String( protoFmt ), "Left: Decimal( 123.456 )", Left );
// Create Decimal values to compare with the reference.
CompareDecimals( Left, Decimal(1.2345600E+2), "Decimal( 1.2345600E+2 )" );
CompareDecimals( Left, Decimal::Parse( "123.4561" ), "Decimal::Parse( \"123.4561\" )" );
CompareDecimals( Left, Decimal::Parse( "123.4559" ), "Decimal::Parse( \"123.4559\" )" );
CompareDecimals( Left, Decimal::Parse( "123.456000" ), "Decimal::Parse( \"123.456000\" )" );
CompareDecimals( Left, Decimal(123456000,0,0,false,6), "Decimal( 123456000, 0, 0, false, 6 )" );
}
/*
This example of the Decimal::Equals( Decimal, Decimal ) and
Decimal::Compare( Decimal, Decimal ) methods generates the
following output. It creates several different Decimal
values and compares them with the following reference value.
Left: Decimal( 123.456 ) 123.456
Right: Decimal( 1.2345600E+2 ) 123.456
Decimal::Equals( Left, Right ) True
Decimal::Compare( Left, Right ) 0
Right: Decimal::Parse( "123.4561" ) 123.4561
Decimal::Equals( Left, Right ) False
Decimal::Compare( Left, Right ) -1
Right: Decimal::Parse( "123.4559" ) 123.4559
Decimal::Equals( Left, Right ) False
Decimal::Compare( Left, Right ) 1
Right: Decimal::Parse( "123.456000" ) 123.456000
Decimal::Equals( Left, Right ) True
Decimal::Compare( Left, Right ) 0
Right: Decimal( 123456000, 0, 0, false, 6 ) 123.456000
Decimal::Equals( Left, Right ) True
Decimal::Compare( Left, Right ) 0
*/
// Example of the decimal.Compare and static decimal.Equals methods.
using System;
class DecCompareEqualsDemo
{
const string dataFmt = "{0,-45}{1}";
// Compare decimal parameters, and display them with the results.
public static void CompareDecimals( decimal Left, decimal Right,
string RightText )
{
Console.WriteLine( );
Console.WriteLine( dataFmt, "Right: "+RightText, Right );
Console.WriteLine( dataFmt, "decimal.Equals( Left, Right )",
Decimal.Equals( Left, Right ) );
Console.WriteLine( dataFmt, "decimal.Compare( Left, Right )",
Decimal.Compare( Left, Right ) );
}
public static void Main( )
{
Console.WriteLine( "This example of the " +
"decimal.Equals( decimal, decimal ) and \n" +
"decimal.Compare( decimal, decimal ) methods " +
"generates the \nfollowing output. It creates several " +
"different decimal \nvalues and compares them with " +
"the following reference value.\n" );
// Create a reference decimal value.
decimal Left = new decimal( 123.456 );
Console.WriteLine( dataFmt, "Left: decimal( 123.456 )",
Left );
// Create decimal values to compare with the reference.
CompareDecimals( Left, new decimal( 1.2345600E+2 ),
"decimal( 1.2345600E+2 )" );
CompareDecimals( Left, 123.4561M, "123.4561M" );
CompareDecimals( Left, 123.4559M, "123.4559M" );
CompareDecimals( Left, 123.456000M, "123.456000M" );
CompareDecimals( Left,
new decimal( 123456000, 0, 0, false, 6 ),
"decimal( 123456000, 0, 0, false, 6 )" );
}
}
/*
This example of the decimal.Equals( decimal, decimal ) and
decimal.Compare( decimal, decimal ) methods generates the
following output. It creates several different decimal
values and compares them with the following reference value.
Left: decimal( 123.456 ) 123.456
Right: decimal( 1.2345600E+2 ) 123.456
decimal.Equals( Left, Right ) True
decimal.Compare( Left, Right ) 0
Right: 123.4561M 123.4561
decimal.Equals( Left, Right ) False
decimal.Compare( Left, Right ) -1
Right: 123.4559M 123.4559
decimal.Equals( Left, Right ) False
decimal.Compare( Left, Right ) 1
Right: 123.456000M 123.456000
decimal.Equals( Left, Right ) True
decimal.Compare( Left, Right ) 0
Right: decimal( 123456000, 0, 0, false, 6 ) 123.456000
decimal.Equals( Left, Right ) True
decimal.Compare( Left, Right ) 0
*/
// Example of the decimal.Compare and static decimal.Equals methods.
open System
let print message obj = printfn $"%-45s{message}{obj}"
// Compare decimal parameters, and display them with the results.
let compareDecimals (left: decimal) (right: decimal) (rightText: string) =
printfn ""
print $"right: {rightText}" right
print "decimal.Equals(left, right) " (Decimal.Equals(left, right))
print "decimal.Compare(left, right) " (Decimal.Compare(left, right))
Console.WriteLine( "This example of the " +
"decimal.Equals(decimal, decimal) and \n" +
"decimal.Compare(decimal, decimal) methods " +
"generates the \nfollowing output. It creates several " +
"different decimal \nvalues and compares them with " +
"the following reference value.\n" )
// Create a reference decimal value.
let left = decimal 123.456
print "left: decimal( 123.456 )" left
// Create decimal values to compare with the reference.
compareDecimals left (decimal 1.2345600E+2 ) "decimal(1.2345600E+2)"
compareDecimals left 123.4561M "123.4561M"
compareDecimals left 123.4559M "123.4559M"
compareDecimals left 123.456000M "123.456000M"
compareDecimals left (Decimal(123456000, 0, 0, false, 6uy)) "Decimal(123456000, 0, 0, false, 6)"
// This example of the decimal.Equals(decimal, decimal) and
// decimal.Compare(decimal, decimal) methods generates the
// following output. It creates several different decimal
// values and compares them with the following reference value.
// left: decimal(123.456) 123.456
// right: decimal(1.2345600E+2) 123.456
// decimal.Equals(left, right) True
// decimal.Compare(left, right) 0
// right: 123.4561M 123.4561
// decimal.Equals(left, right) False
// decimal.Compare(left, right) -1
// right: 123.4559M 123.4559
// decimal.Equals(left, right) False
// decimal.Compare(left, right) 1
// right: 123.456000M 123.456000
// decimal.Equals(left, right) True
// decimal.Compare(left, right) 0
// right: decimal(123456000, 0, 0, false, 6) 123.456000
// decimal.Equals(left, right) True
// decimal.Compare(left, right) 0
' Example of the Decimal.Compare and static Decimal.Equals methods.
Module DecCompareEqualsDemo
Const dataFmt As String = "{0,-45}{1}"
' Compare Decimal parameters, and display them with the results.
Sub CompareDecimals( Left as Decimal, Right as Decimal, _
RightText as String )
Console.WriteLine( )
Console.WriteLine( dataFmt, "Right: " & RightText, Right )
Console.WriteLine( dataFmt, "Decimal.Equals( Left, Right )", _
Decimal.Equals( Left, Right ) )
Console.WriteLine( dataFmt, _
"Decimal.Compare( Left, Right )", _
Decimal.Compare( Left, Right ) )
End Sub
Sub Main( )
Console.WriteLine( _
"This example of the Decimal.Equals( Decimal, " & _
"Decimal ) and " & vbCrLf & "Decimal.Compare( " & _
"Decimal, Decimal ) methods generates the " & vbCrLf & _
"following output. It creates several different " & _
"Decimal " & vbCrLf & "values and compares them " & _
"with the following reference value." & vbCrLf )
' Create a reference Decimal value.
Dim Left as New Decimal( 123.456 )
Console.WriteLine( dataFmt, "Left: Decimal( 123.456 )", Left )
' Create Decimal values to compare with the reference.
CompareDecimals( Left, New Decimal( 1.2345600E+2 ), _
"Decimal( 1.2345600E+2 )" )
CompareDecimals( Left, 123.4561D, "123.4561D" )
CompareDecimals( Left, 123.4559D, "123.4559D" )
CompareDecimals( Left, 123.456000D, "123.456000D" )
CompareDecimals( Left, _
New Decimal( 123456000, 0, 0, false, 6 ), _
"Decimal( 123456000, 0, 0, false, 6 )" )
End Sub
End Module
' This example of the Decimal.Equals( Decimal, Decimal ) and
' Decimal.Compare( Decimal, Decimal ) methods generates the
' following output. It creates several different Decimal
' values and compares them with the following reference value.
'
' Left: Decimal( 123.456 ) 123.456
'
' Right: Decimal( 1.2345600E+2 ) 123.456
' Decimal.Equals( Left, Right ) True
' Decimal.Compare( Left, Right ) 0
'
' Right: 123.4561D 123.4561
' Decimal.Equals( Left, Right ) False
' Decimal.Compare( Left, Right ) -1
'
' Right: 123.4559D 123.4559
' Decimal.Equals( Left, Right ) False
' Decimal.Compare( Left, Right ) 1
'
' Right: 123.456000D 123.456
' Decimal.Equals( Left, Right ) True
' Decimal.Compare( Left, Right ) 0
'
' Right: Decimal( 123456000, 0, 0, false, 6 ) 123.456000
' Decimal.Equals( Left, Right ) True
' Decimal.Compare( Left, Right ) 0
另请参阅
适用于
Equals(Decimal)
- Source:
- Decimal.cs
- Source:
- Decimal.cs
- Source:
- Decimal.cs
返回一个值,该值指示此实例和指定的 Decimal 对象是否表示相同的值。
public:
virtual bool Equals(System::Decimal value);
public bool Equals (decimal value);
override this.Equals : decimal -> bool
Public Function Equals (value As Decimal) As Boolean
参数
- value
- Decimal
要与此实例进行比较的对象。
返回
如果 value
等于此实例,则 true
;否则,false
。
实现
注解
此方法实现 System.IEquatable<T> 接口,并且性能略高于 Equals,因为它不必将 value
参数转换为对象。
如果 value
的位数(比实例类型更窄),则某些编程语言会执行隐式扩展转换,将参数的值转换为具有更多位的值。
例如,假设实例类型 Int32,参数类型 Byte。 Microsoft C# 编译器生成将参数值表示为 Int32 对象的指令,然后生成 Int32.CompareTo 方法来比较 Int32 实例和参数表示形式。
请参阅编程语言的文档,以确定其编译器是否对数值类型执行隐式扩展转换。
调用方说明
编译器重载解析可能会导致两个 Equals(Object) 方法重载的行为明显差异。 如果定义了 value
自变量与 Decimal 之间的隐式转换,并且该参数未键入为 Object,编译器可以执行隐式转换并调用 Equals(Decimal) 方法。 否则,它们将调用 Equals(Object) 方法,如果 value
参数不是 Decimal 值,则始终返回 false
。 下面的示例说明了两个方法重载的行为差异。 对于所有基元整型类型(包括有符号和无符号类型)的情况,第一个比较返回 true
,因为编译器会自动执行扩大转换并调用 Equals(Decimal) 方法,而第二个比较返回 false
,因为编译器调用 Equals(Object) 方法。
using System;
public class Example
{
static decimal value = 112m;
public static void Main()
{
byte byte1= 112;
Console.WriteLine("value = byte1: {0,17}", value.Equals(byte1));
TestObjectForEquality(byte1);
short short1 = 112;
Console.WriteLine("value = short1: {0,17}", value.Equals(short1));
TestObjectForEquality(short1);
int int1 = 112;
Console.WriteLine("value = int1: {0,19}", value.Equals(int1));
TestObjectForEquality(int1);
long long1 = 112;
Console.WriteLine("value = long1: {0,18}", value.Equals(long1));
TestObjectForEquality(long1);
sbyte sbyte1 = 112;
Console.WriteLine("value = sbyte1: {0,17}", value.Equals(sbyte1));
TestObjectForEquality(sbyte1);
ushort ushort1 = 112;
Console.WriteLine("value = ushort1: {0,17}", value.Equals(ushort1));
TestObjectForEquality(ushort1);
uint uint1 = 112;
Console.WriteLine("value = uint1: {0,19}", value.Equals(uint1));
TestObjectForEquality(uint1);
ulong ulong1 = 112;
Console.WriteLine("value = ulong1: {0,18}", value.Equals(ulong1));
TestObjectForEquality(ulong1);
float sng1 = 112;
Console.WriteLine("value = sng1: {0,21}", value.Equals(sng1));
TestObjectForEquality(sng1);
double dbl1 = 112;
Console.WriteLine("value = dbl1: {0,21}", value.Equals(dbl1));
TestObjectForEquality(dbl1);
}
private static void TestObjectForEquality(Object obj)
{
Console.WriteLine("{0} ({1}) = {2} ({3}): {4}\n",
value, value.GetType().Name,
obj, obj.GetType().Name,
value.Equals(obj));
}
}
// The example displays the following output:
// value = byte1: True
// 112 (Decimal) = 112 (Byte): False
//
// value = short1: True
// 112 (Decimal) = 112 (Int16): False
//
// value = int1: True
// 112 (Decimal) = 112 (Int32): False
//
// value = long1: True
// 112 (Decimal) = 112 (Int64): False
//
// value = sbyte1: True
// 112 (Decimal) = 112 (SByte): False
//
// value = ushort1: True
// 112 (Decimal) = 112 (UInt16): False
//
// value = uint1: True
// 112 (Decimal) = 112 (UInt32): False
//
// value = ulong1: True
// 112 (Decimal) = 112 (UInt64): False
//
// value = sng1: False
// 112 (Decimal) = 112 (Single): False
//
// value = dbl1: False
// 112 (Decimal) = 112 (Double): False
let value = 112m
let testObjectForEquality (obj: obj) =
printfn $"{value} ({value.GetType().Name}) = {obj} ({obj.GetType().Name}): {value.Equals obj}\n"
let byte1 = 112uy
printfn $"value = byte1: {value.Equals byte1,17}"
testObjectForEquality byte1
let short1 = 112s
printfn $"value = short1: {value.Equals short1,17}"
testObjectForEquality short1
let int1 = 112
printfn $"value = int1: {value.Equals int1,19}"
testObjectForEquality int1
let long1 = 112L
printfn $"value = long1: {value.Equals long1,18}"
testObjectForEquality long1
let sbyte1 = 112y
printfn $"value = sbyte1: {value.Equals sbyte1,17}"
testObjectForEquality sbyte1
let ushort1 = 112us
printfn $"value = ushort1: {value.Equals ushort1,17}"
testObjectForEquality ushort1
let uint1 = 112u
printfn $"value = uint1: {value.Equals uint1,19}"
testObjectForEquality uint1
let ulong1 = 112uL
printfn $"value = ulong1: {value.Equals ulong1,18}"
testObjectForEquality ulong1
let sng1 = 112f
printfn $"value = sng1: {value.Equals sng1,21}"
testObjectForEquality sng1
let dbl1 = 112.
printfn $"value = dbl1: {value.Equals dbl1,21}"
testObjectForEquality dbl1
// The example displays the following output:
// value = byte1: True
// 112 (Decimal) = 112 (Byte): False
//
// value = short1: True
// 112 (Decimal) = 112 (Int16): False
//
// value = int1: True
// 112 (Decimal) = 112 (Int32): False
//
// value = long1: True
// 112 (Decimal) = 112 (Int64): False
//
// value = sbyte1: True
// 112 (Decimal) = 112 (SByte): False
//
// value = ushort1: True
// 112 (Decimal) = 112 (UInt16): False
//
// value = uint1: True
// 112 (Decimal) = 112 (UInt32): False
//
// value = ulong1: True
// 112 (Decimal) = 112 (UInt64): False
//
// value = sng1: False
// 112 (Decimal) = 112 (Single): False
//
// value = dbl1: False
// 112 (Decimal) = 112 (Double): False
Module Example
Dim value As Decimal = 112d
Public Sub Main()
Dim byte1 As Byte = 112
Console.WriteLine("value = byte1: {0,17}", value.Equals(byte1))
TestObjectForEquality(byte1)
Dim short1 As Short = 112
Console.WriteLine("value = short1: {0,17}", value.Equals(short1))
TestObjectForEquality(short1)
Dim int1 As Integer = 112
Console.WriteLine("value = int1: {0,19}", value.Equals(int1))
TestObjectForEquality(int1)
Dim long1 As Long = 112
Console.WriteLine("value = long1: {0,18}", value.Equals(long1))
TestObjectForEquality(long1)
Dim sbyte1 As SByte = 112
Console.WriteLine("value = sbyte1: {0,17}", value.Equals(sbyte1))
TestObjectForEquality(sbyte1)
Dim ushort1 As UShort = 112
Console.WriteLine("value = ushort1: {0,17}", value.Equals(ushort1))
TestObjectForEquality(ushort1)
Dim uint1 As UInteger = 112
Console.WriteLine("value = uint1: {0,19}", value.Equals(uint1))
TestObjectForEquality(uint1)
Dim ulong1 As ULong = 112
Console.WriteLine("value = ulong1: {0,18}", value.Equals(ulong1))
TestObjectForEquality(ulong1)
Dim sng1 As Single = 112
Console.WriteLine("value = sng1: {0,21}", value.Equals(sng1))
TestObjectForEquality(sng1)
Dim dbl1 As Double = 112
Console.WriteLine("value = dbl1: {0,21}", value.Equals(dbl1))
TestObjectForEquality(dbl1)
End Sub
Private Sub TestObjectForEquality(obj As Object)
Console.WriteLine("{0} ({1}) = {2} ({3}): {4}",
value, value.GetType().Name,
obj, obj.GetType().Name,
value.Equals(obj))
Console.WriteLine()
End Sub
End Module
' The example displays the following output:
' value = byte1: True
' 112 (Decimal) = 112 (Byte): False
'
' value = short1: True
' 112 (Decimal) = 112 (Int16): False
'
' value = int1: True
' 112 (Decimal) = 112 (Int32): False
'
' value = long1: True
' 112 (Decimal) = 112 (Int64): False
'
' value = sbyte1: True
' 112 (Decimal) = 112 (SByte): False
'
' value = ushort1: True
' 112 (Decimal) = 112 (UInt16): False
'
' value = uint1: True
' 112 (Decimal) = 112 (UInt32): False
'
' value = ulong1: True
' 112 (Decimal) = 112 (UInt64): False
'
' value = sng1: False
' 112 (Decimal) = 112 (Single): False
'
' value = dbl1: False
' 112 (Decimal) = 112 (Double): False
另请参阅
适用于
Equals(Object)
- Source:
- Decimal.cs
- Source:
- Decimal.cs
- Source:
- Decimal.cs
返回一个值,该值指示此实例和指定的 Object 是否表示相同的类型和值。
public:
override bool Equals(System::Object ^ value);
public override bool Equals (object value);
public override bool Equals (object? value);
override this.Equals : obj -> bool
Public Overrides Function Equals (value As Object) As Boolean
参数
- value
- Object
要与此实例进行比较的对象。
返回
如果 value
是 Decimal 且等于此实例,则 true
;否则,false
。
示例
下面的代码示例使用 Equals
方法将多个 Decimal
和其他对象与引用 Decimal
值进行比较。
// Example of the Decimal::CompareTo and Decimal::Equals instance
// methods.
using namespace System;
// Get the exception type name; remove the namespace prefix.
String^ GetExceptionType( Exception^ ex )
{
String^ exceptionType = ex->GetType()->ToString();
return exceptionType->Substring( exceptionType->LastIndexOf( '.' ) + 1 );
}
// Compare the Decimal to the Object parameters,
// and display the Object parameters with the results.
void CompDecimalToObject( Decimal Left, Object^ Right, String^ RightText )
{
Console::WriteLine( "{0,-46}{1}", String::Concat( "Object: ", RightText ), Right );
Console::WriteLine( "{0,-46}{1}", "Left.Equals( Object )", Left.Equals( Right ) );
Console::Write( "{0,-46}", "Left.CompareTo( Object )" );
try
{
// Catch the exception if CompareTo( ) throws one.
Console::WriteLine( "{0}\n", Left.CompareTo( Right ) );
}
catch ( Exception^ ex )
{
Console::WriteLine( "{0}\n", GetExceptionType( ex ) );
}
}
int main()
{
Console::WriteLine( "This example of the Decimal::Equals( Object* ) and \n"
"Decimal::CompareTo( Object* ) methods generates the \n"
"following output. It creates several different "
"Decimal \nvalues and compares them with the following "
"reference value.\n" );
// Create a reference Decimal value.
Decimal Left = Decimal(987.654);
Console::WriteLine( "{0,-46}{1}\n", "Left: Decimal( 987.654 )", Left );
// Create objects to compare with the reference.
CompDecimalToObject( Left, Decimal(9.8765400E+2), "Decimal( 9.8765400E+2 )" );
CompDecimalToObject( Left, Decimal::Parse( "987.6541" ), "Decimal::Parse( \"987.6541\" )" );
CompDecimalToObject( Left, Decimal::Parse( "987.6539" ), "Decimal::Parse( \"987.6539\" )" );
CompDecimalToObject( Left, Decimal(987654000,0,0,false,6), "Decimal( 987654000, 0, 0, false, 6 )" );
CompDecimalToObject( Left, 9.8765400E+2, "Double 9.8765400E+2" );
CompDecimalToObject( Left, "987.654", "String \"987.654\"" );
}
/*
This example of the Decimal::Equals( Object* ) and
Decimal::CompareTo( Object* ) methods generates the
following output. It creates several different Decimal
values and compares them with the following reference value.
Left: Decimal( 987.654 ) 987.654
Object: Decimal( 9.8765400E+2 ) 987.654
Left.Equals( Object ) True
Left.CompareTo( Object ) 0
Object: Decimal::Parse( "987.6541" ) 987.6541
Left.Equals( Object ) False
Left.CompareTo( Object ) -1
Object: Decimal::Parse( "987.6539" ) 987.6539
Left.Equals( Object ) False
Left.CompareTo( Object ) 1
Object: Decimal( 987654000, 0, 0, false, 6 ) 987.654000
Left.Equals( Object ) True
Left.CompareTo( Object ) 0
Object: Double 9.8765400E+2 987.654
Left.Equals( Object ) False
Left.CompareTo( Object ) ArgumentException
Object: String "987.654" 987.654
Left.Equals( Object ) False
Left.CompareTo( Object ) ArgumentException
*/
// Example of the decimal.CompareTo and decimal.Equals instance
// methods.
using System;
class DecCompToEqualsObjDemo
{
// Get the exception type name; remove the namespace prefix.
public static string GetExceptionType( Exception ex )
{
string exceptionType = ex.GetType( ).ToString( );
return exceptionType.Substring(
exceptionType.LastIndexOf( '.' ) + 1 );
}
// Compare the decimal to the object parameters,
// and display the object parameters with the results.
public static void CompDecimalToObject( decimal Left,
object Right, string RightText )
{
Console.WriteLine( "{0,-46}{1}", "object: "+RightText,
Right );
Console.WriteLine( "{0,-46}{1}", "Left.Equals( object )",
Left.Equals( Right ) );
Console.Write( "{0,-46}", "Left.CompareTo( object )" );
try
{
// Catch the exception if CompareTo( ) throws one.
Console.WriteLine( "{0}\n", Left.CompareTo( Right ) );
}
catch( Exception ex )
{
Console.WriteLine( "{0}\n", GetExceptionType( ex ) );
}
}
public static void Main( )
{
Console.WriteLine(
"This example of the decimal.Equals( object ) and \n" +
"decimal.CompareTo( object ) methods generates the \n" +
"following output. It creates several different " +
"decimal \nvalues and compares them with the following " +
"reference value.\n" );
// Create a reference decimal value.
decimal Left = new decimal( 987.654 );
Console.WriteLine( "{0,-46}{1}\n",
"Left: decimal( 987.654 )", Left );
// Create objects to compare with the reference.
CompDecimalToObject( Left, new decimal( 9.8765400E+2 ),
"decimal( 9.8765400E+2 )" );
CompDecimalToObject( Left, 987.6541M, "987.6541D" );
CompDecimalToObject( Left, 987.6539M, "987.6539D" );
CompDecimalToObject( Left,
new decimal( 987654000, 0, 0, false, 6 ),
"decimal( 987654000, 0, 0, false, 6 )" );
CompDecimalToObject( Left, 9.8765400E+2,
"Double 9.8765400E+2" );
CompDecimalToObject( Left, "987.654", "String \"987.654\"" );
}
}
/*
This example of the decimal.Equals( object ) and
decimal.CompareTo( object ) methods generates the
following output. It creates several different decimal
values and compares them with the following reference value.
Left: decimal( 987.654 ) 987.654
object: decimal( 9.8765400E+2 ) 987.654
Left.Equals( object ) True
Left.CompareTo( object ) 0
object: 987.6541D 987.6541
Left.Equals( object ) False
Left.CompareTo( object ) -1
object: 987.6539D 987.6539
Left.Equals( object ) False
Left.CompareTo( object ) 1
object: decimal( 987654000, 0, 0, false, 6 ) 987.654000
Left.Equals( object ) True
Left.CompareTo( object ) 0
object: Double 9.8765400E+2 987.654
Left.Equals( object ) False
Left.CompareTo( object ) ArgumentException
object: String "987.654" 987.654
Left.Equals( object ) False
Left.CompareTo( object ) ArgumentException
*/
// Example of the decimal.CompareTo and decimal.Equals instance
// methods.
open System
// Get the exception type name remove the namespace prefix.
let getExceptionType (ex: exn) =
let exceptionType = ex.GetType() |> string
exceptionType.Substring(exceptionType.LastIndexOf '.' + 1)
// Compare the decimal to the object parameters,
// and display the object parameters with the results.
let compDecimalToObject (left: decimal) (right: obj) (rightText: string) =
printfn $"object: %-38s{rightText}{right}"
printfn $"""%-46s{"left.Equals(object)"}{left.Equals right}"""
printf $"""%-46s{"left.CompareTo(object)"}"""
try
// Catch the exception if CompareTo( ) throws one.
printfn $"{left.CompareTo right}\n"
with ex ->
printfn $"{getExceptionType ex}\n"
Console.WriteLine(
"This example of the decimal.Equals( object ) and \n" +
"decimal.CompareTo( object ) methods generates the \n" +
"following output. It creates several different " +
"decimal \nvalues and compares them with the following " +
"reference value.\n" )
// Create a reference decimal value.
let left = decimal 987.654
printfn $"""{"Left: decimal(987.654)",-46}{left}\n"""
// Create objects to compare with the reference.
compDecimalToObject left (decimal 9.8765400E+2 ) "decimal(9.8765400E+2)"
compDecimalToObject left 987.6541M "987.6541D"
compDecimalToObject left 987.6539M "987.6539D"
compDecimalToObject left (Decimal(987654000, 0, 0, false, 6uy)) "Decimal(987654000, 0, 0, false, 6)"
compDecimalToObject left 9.8765400E+2 "Double 9.8765400E+2"
compDecimalToObject left "987.654" "String \"987.654\""
// This example of the Decimal.Equals(object) and
// Decimal.CompareTo(object) methods generates the
// following output. It creates several different decimal
// values and compares them with the following reference value.
// Left: decimal(987.654) 987.654
//
// object: decimal(9.8765400E+2) 987.654
// left.Equals(object) True
// left.CompareTo(object) 0
//
// object: 987.6541D 987.6541
// left.Equals(object) False
// left.CompareTo(object) -1
//
// object: 987.6539D 987.6539
// left.Equals(object) False
// left.CompareTo(object) 1
//
// object: Decimal(987654000, 0, 0, false, 6) 987.654000
// left.Equals(object) True
// left.CompareTo(object) 0
//
// object: Double 9.8765400E+2 987.654
// left.Equals(object) False
// left.CompareTo(object) ArgumentException
//
// object: String "987.654" 987.654
// left.Equals(object) False
// left.CompareTo(object) ArgumentException
' Example of the Decimal.CompareTo and Decimal.Equals instance methods.
Module DecCompToEqualsObjDemo
' Get the exception type name; remove the namespace prefix.
Function GetExceptionType( ex As Exception ) As String
Dim exceptionType As String = ex.GetType( ).ToString( )
Return exceptionType.Substring( _
exceptionType.LastIndexOf( "."c ) + 1 )
End Function
' Compare the Decimal to the Object parameters,
' and display the Object parameters with the results.
Sub CompDecimalToObject( Left as Decimal, Right as Object, _
RightText as String )
Console.WriteLine( "{0,-46}{1}", "Object: " & RightText, _
Right )
Console.WriteLine( "{0,-46}{1}", "Left.Equals( Object )", _
Left.Equals( Right ) )
Console.Write( "{0,-46}", "Left.CompareTo( Object )" )
' Catch the exception if CompareTo( ) throws one.
Try
Console.WriteLine( "{0}" & vbCrLf, _
Left.CompareTo( Right ) )
Catch ex As Exception
Console.WriteLine( "{0}" & vbCrLf, _
GetExceptionType( ex ) )
End Try
End Sub
Sub Main( )
Console.WriteLine( _
"This example of the Decimal.Equals( Object ) " & _
"and " & vbCrLf & "Decimal.CompareTo( Object ) " & _
"methods generates the " & vbCrLf & _
"following output. It creates several different " & _
"Decimal " & vbCrLf & "values and compares them " & _
"with the following reference value." & vbCrLf )
' Create a reference Decimal value.
Dim Left as New Decimal( 987.654 )
Console.WriteLine( "{0,-46}{1}" & vbCrLf, _
"Left: Decimal( 987.654 )", Left )
' Create objects to compare with the reference.
CompDecimalToObject( Left, New Decimal( 9.8765400E+2 ), _
"Decimal( 9.8765400E+2 )" )
CompDecimalToObject( Left, 987.6541D, "987.6541D" )
CompDecimalToObject( Left, 987.6539D, "987.6539D" )
CompDecimalToObject( Left, _
New Decimal( 987654000, 0, 0, false, 6 ), _
"Decimal( 987654000, 0, 0, false, 6 )" )
CompDecimalToObject( Left, 9.8765400E+2, _
"Double 9.8765400E+2" )
CompDecimalToObject( Left, "987.654", _
"String ""987.654""" )
End Sub
End Module
' This example of the Decimal.Equals( Object ) and
' Decimal.CompareTo( Object ) methods generates the
' following output. It creates several different Decimal
' values and compares them with the following reference value.
'
' Left: Decimal( 987.654 ) 987.654
'
' Object: Decimal( 9.8765400E+2 ) 987.654
' Left.Equals( Object ) True
' Left.CompareTo( Object ) 0
'
' Object: 987.6541D 987.6541
' Left.Equals( Object ) False
' Left.CompareTo( Object ) -1
'
' Object: 987.6539D 987.6539
' Left.Equals( Object ) False
' Left.CompareTo( Object ) 1
'
' Object: Decimal( 987654000, 0, 0, false, 6 ) 987.654000
' Left.Equals( Object ) True
' Left.CompareTo( Object ) 0
'
' Object: Double 9.8765400E+2 987.654
' Left.Equals( Object ) False
' Left.CompareTo( Object ) ArgumentException
'
' Object: String "987.654" 987.654
' Left.Equals( Object ) False
' Left.CompareTo( Object ) ArgumentException
调用方说明
编译器重载解析可能会导致两个 Equals(Object) 方法重载的行为明显差异。 如果定义了 value
自变量与 Decimal 之间的隐式转换,并且该参数未键入为 Object,编译器可以执行隐式转换并调用 Equals(Decimal) 方法。 否则,它们将调用 Equals(Object) 方法,如果 value
参数不是 Decimal 值,则始终返回 false
。 下面的示例说明了两个方法重载的行为差异。 对于所有基元整型类型(包括有符号和无符号类型)的情况,第一个比较返回 true
,因为编译器会自动执行扩大转换并调用 Equals(Decimal) 方法,而第二个比较返回 false
,因为编译器调用 Equals(Object) 方法。
using System;
public class Example
{
static decimal value = 112m;
public static void Main()
{
byte byte1= 112;
Console.WriteLine("value = byte1: {0,17}", value.Equals(byte1));
TestObjectForEquality(byte1);
short short1 = 112;
Console.WriteLine("value = short1: {0,17}", value.Equals(short1));
TestObjectForEquality(short1);
int int1 = 112;
Console.WriteLine("value = int1: {0,19}", value.Equals(int1));
TestObjectForEquality(int1);
long long1 = 112;
Console.WriteLine("value = long1: {0,18}", value.Equals(long1));
TestObjectForEquality(long1);
sbyte sbyte1 = 112;
Console.WriteLine("value = sbyte1: {0,17}", value.Equals(sbyte1));
TestObjectForEquality(sbyte1);
ushort ushort1 = 112;
Console.WriteLine("value = ushort1: {0,17}", value.Equals(ushort1));
TestObjectForEquality(ushort1);
uint uint1 = 112;
Console.WriteLine("value = uint1: {0,19}", value.Equals(uint1));
TestObjectForEquality(uint1);
ulong ulong1 = 112;
Console.WriteLine("value = ulong1: {0,18}", value.Equals(ulong1));
TestObjectForEquality(ulong1);
float sng1 = 112;
Console.WriteLine("value = sng1: {0,21}", value.Equals(sng1));
TestObjectForEquality(sng1);
double dbl1 = 112;
Console.WriteLine("value = dbl1: {0,21}", value.Equals(dbl1));
TestObjectForEquality(dbl1);
}
private static void TestObjectForEquality(Object obj)
{
Console.WriteLine("{0} ({1}) = {2} ({3}): {4}\n",
value, value.GetType().Name,
obj, obj.GetType().Name,
value.Equals(obj));
}
}
// The example displays the following output:
// value = byte1: True
// 112 (Decimal) = 112 (Byte): False
//
// value = short1: True
// 112 (Decimal) = 112 (Int16): False
//
// value = int1: True
// 112 (Decimal) = 112 (Int32): False
//
// value = long1: True
// 112 (Decimal) = 112 (Int64): False
//
// value = sbyte1: True
// 112 (Decimal) = 112 (SByte): False
//
// value = ushort1: True
// 112 (Decimal) = 112 (UInt16): False
//
// value = uint1: True
// 112 (Decimal) = 112 (UInt32): False
//
// value = ulong1: True
// 112 (Decimal) = 112 (UInt64): False
//
// value = sng1: False
// 112 (Decimal) = 112 (Single): False
//
// value = dbl1: False
// 112 (Decimal) = 112 (Double): False
let value = 112m
let testObjectForEquality (obj: obj) =
printfn $"{value} ({value.GetType().Name}) = {obj} ({obj.GetType().Name}): {value.Equals obj}\n"
let byte1 = 112uy
printfn $"value = byte1: {value.Equals byte1,17}"
testObjectForEquality byte1
let short1 = 112s
printfn $"value = short1: {value.Equals short1,17}"
testObjectForEquality short1
let int1 = 112
printfn $"value = int1: {value.Equals int1,19}"
testObjectForEquality int1
let long1 = 112L
printfn $"value = long1: {value.Equals long1,18}"
testObjectForEquality long1
let sbyte1 = 112y
printfn $"value = sbyte1: {value.Equals sbyte1,17}"
testObjectForEquality sbyte1
let ushort1 = 112us
printfn $"value = ushort1: {value.Equals ushort1,17}"
testObjectForEquality ushort1
let uint1 = 112u
printfn $"value = uint1: {value.Equals uint1,19}"
testObjectForEquality uint1
let ulong1 = 112uL
printfn $"value = ulong1: {value.Equals ulong1,18}"
testObjectForEquality ulong1
let sng1 = 112f
printfn $"value = sng1: {value.Equals sng1,21}"
testObjectForEquality sng1
let dbl1 = 112.
printfn $"value = dbl1: {value.Equals dbl1,21}"
testObjectForEquality dbl1
// The example displays the following output:
// value = byte1: True
// 112 (Decimal) = 112 (Byte): False
//
// value = short1: True
// 112 (Decimal) = 112 (Int16): False
//
// value = int1: True
// 112 (Decimal) = 112 (Int32): False
//
// value = long1: True
// 112 (Decimal) = 112 (Int64): False
//
// value = sbyte1: True
// 112 (Decimal) = 112 (SByte): False
//
// value = ushort1: True
// 112 (Decimal) = 112 (UInt16): False
//
// value = uint1: True
// 112 (Decimal) = 112 (UInt32): False
//
// value = ulong1: True
// 112 (Decimal) = 112 (UInt64): False
//
// value = sng1: False
// 112 (Decimal) = 112 (Single): False
//
// value = dbl1: False
// 112 (Decimal) = 112 (Double): False
Module Example
Dim value As Decimal = 112d
Public Sub Main()
Dim byte1 As Byte = 112
Console.WriteLine("value = byte1: {0,17}", value.Equals(byte1))
TestObjectForEquality(byte1)
Dim short1 As Short = 112
Console.WriteLine("value = short1: {0,17}", value.Equals(short1))
TestObjectForEquality(short1)
Dim int1 As Integer = 112
Console.WriteLine("value = int1: {0,19}", value.Equals(int1))
TestObjectForEquality(int1)
Dim long1 As Long = 112
Console.WriteLine("value = long1: {0,18}", value.Equals(long1))
TestObjectForEquality(long1)
Dim sbyte1 As SByte = 112
Console.WriteLine("value = sbyte1: {0,17}", value.Equals(sbyte1))
TestObjectForEquality(sbyte1)
Dim ushort1 As UShort = 112
Console.WriteLine("value = ushort1: {0,17}", value.Equals(ushort1))
TestObjectForEquality(ushort1)
Dim uint1 As UInteger = 112
Console.WriteLine("value = uint1: {0,19}", value.Equals(uint1))
TestObjectForEquality(uint1)
Dim ulong1 As ULong = 112
Console.WriteLine("value = ulong1: {0,18}", value.Equals(ulong1))
TestObjectForEquality(ulong1)
Dim sng1 As Single = 112
Console.WriteLine("value = sng1: {0,21}", value.Equals(sng1))
TestObjectForEquality(sng1)
Dim dbl1 As Double = 112
Console.WriteLine("value = dbl1: {0,21}", value.Equals(dbl1))
TestObjectForEquality(dbl1)
End Sub
Private Sub TestObjectForEquality(obj As Object)
Console.WriteLine("{0} ({1}) = {2} ({3}): {4}",
value, value.GetType().Name,
obj, obj.GetType().Name,
value.Equals(obj))
Console.WriteLine()
End Sub
End Module
' The example displays the following output:
' value = byte1: True
' 112 (Decimal) = 112 (Byte): False
'
' value = short1: True
' 112 (Decimal) = 112 (Int16): False
'
' value = int1: True
' 112 (Decimal) = 112 (Int32): False
'
' value = long1: True
' 112 (Decimal) = 112 (Int64): False
'
' value = sbyte1: True
' 112 (Decimal) = 112 (SByte): False
'
' value = ushort1: True
' 112 (Decimal) = 112 (UInt16): False
'
' value = uint1: True
' 112 (Decimal) = 112 (UInt32): False
'
' value = ulong1: True
' 112 (Decimal) = 112 (UInt64): False
'
' value = sng1: False
' 112 (Decimal) = 112 (Single): False
'
' value = dbl1: False
' 112 (Decimal) = 112 (Double): False