Single.Equals Metode

Referensi

Definisi

Ruang nama:: System

Rakitan:: System.Runtime.dll

Rakitan:: mscorlib.dll

Rakitan:: netstandard.dll

Penting

Beberapa informasi terkait produk prarilis yang dapat diubah secara signifikan sebelum dirilis. Microsoft tidak memberikan jaminan, tersirat maupun tersurat, sehubungan dengan informasi yang diberikan di sini.

Mengembalikan nilai yang menunjukkan apakah dua instans Single mewakili nilai yang sama.

Overload

Equals(Object)	Mengembalikan nilai yang menunjukkan apakah instans ini sama dengan objek tertentu.
Equals(Single)	Mengembalikan nilai yang menunjukkan apakah instans ini dan objek tertentu Single mewakili nilai yang sama.

Equals(Object)

Sumber:: Single.cs

Sumber:: Single.cs

Sumber:: Single.cs

Mengembalikan nilai yang menunjukkan apakah instans ini sama dengan objek tertentu.

public:
 override bool Equals(System::Object ^ obj);

public override bool Equals (object obj);

public override bool Equals (object? obj);

override this.Equals : obj -> bool

Public Overrides Function Equals (obj As Object) As Boolean

Parameter

obj: Object

Objek untuk dibandingkan dengan instans ini.

Mengembalikan

Boolean

true jika obj adalah instans dari Single dan sama dengan nilai instans ini; jika tidak, false.

Contoh

Contoh kode berikut menunjukkan Equals metode .

obj1 = (Single)500;

if ( a.Equals( obj1 ) )
{
   Console::WriteLine( "The value type and reference type values are equal." );
}

obj1 = (Single)500;
if (a.Equals(obj1)) {
    Console.WriteLine("The value type and reference type values are equal.");
}

let obj1 = single 500
if a.Equals obj1 then
    printfn "The value type and reference type values are equal."

Obj1 = CType(500, Single)

If A.Equals(Obj1) Then
    Console.WriteLine("The value type and reference type values are equal.")
End If

Keterangan

Metode Equals ini harus digunakan dengan hati-hati, karena dua nilai yang tampaknya setara dapat tidak sama karena presisi yang berbeda dari dua nilai. Contoh berikut melaporkan bahwa Single nilai .3333 dan yang Single dikembalikan dengan membaangan 1 dengan 3 tidak sama.

// Initialize two floats with apparently identical values
float float1 = .33333f;
object float2 = 1/3;
// Compare them for equality
Console.WriteLine(float1.Equals(float2));    // displays false

// Initialize two floats with apparently identical values
let float1 = 0.33333f
let float2 = box (1f / 3f)
// Compare them for equality
printfn $"{float1.Equals float2}"    // displays false

' Initialize two singles with apparently identical values
Dim single1 As Single = .33333
Dim single2 As Object = 1/3
' Compare them for equality
Console.WriteLine(single1.Equals(single2))    ' displays False

Daripada membandingkan untuk kesetaraan, salah satu teknik yang direkomendasikan melibatkan penentuan margin selisih yang dapat diterima antara dua nilai (seperti .01% dari salah satu nilai). Jika nilai absolut perbedaan antara kedua nilai kurang dari atau sama dengan margin tersebut, perbedaannya kemungkinan disebabkan oleh perbedaan presisi dan, oleh karena itu, nilainya kemungkinan sama. Contoh berikut menggunakan teknik ini untuk membandingkan .33333 dan 1/3, dua Single nilai yang ditemukan contoh kode sebelumnya tidak sama.

// Initialize two floats with apparently identical values
float float1 = .33333f;
object float2 = (float) 1/3;
// Define the tolerance for variation in their values
float difference = Math.Abs(float1 * .0001f);

// Compare the values
// The output to the console indicates that the two values are equal
if (Math.Abs(float1 - (float) float2) <= difference)
   Console.WriteLine("float1 and float2 are equal.");
else
   Console.WriteLine("float1 and float2 are unequal.");

// Initialize two floats with apparently identical values
let float1 = 0.33333f
let float2 = box (1f / 3f)
// Define the tolerance for variation in their values
let difference = abs (float1 * 0.0001f)

// Compare the values
// The output to the console indicates that the two values are equal
if abs (float1 - (float2 :?> float32)) <= difference then
    printfn "float1 and float2 are equal."
else
    printfn "float1 and float2 are unequal."

' Initialize two singles with apparently identical values
Dim single1 As Single = .33333
Dim single2 As Object = 1/3
' Define the tolerance for variation in their values
Dim difference As Single = Math.Abs(single1 * .0001f)

' Compare the values
' The output to the console indicates that the two values are equal
If Math.Abs(single1 - CSng(single2)) <= difference Then
   Console.WriteLine("single1 and single2 are equal.")
Else
   Console.WriteLine("single1 and single2 are unequal.")
End If

Dalam hal ini, nilainya sama.

Catatan

Karena Epsilon mendefinisikan ekspresi minimum nilai positif yang rentangnya mendekati nol, margin perbedaan harus lebih besar dari Epsilon. Biasanya, berkali-kali lebih besar dari Epsilon.

Presisi angka floating-point di luar presisi yang di dokumentasi khusus untuk implementasi dan versi .NET Framework. Akibatnya, perbandingan dua angka tertentu mungkin berubah di antara versi .NET Framework karena presisi representasi internal angka mungkin berubah.

Catatan Bagi Pemanggil

Resolusi kelebihan beban pengkompilasi dapat memperhitungkan perbedaan yang jelas dalam perilaku dua Equals(Object) metode kelebihan beban. Jika konversi implisit antara obj argumen dan didefinisikan Single dan argumen tidak di ketik sebagai Object, kompilator dapat melakukan konversi implisit dan memanggil Equals(Single) metode . Jika tidak, mereka memanggil Equals(Object) metode , yang selalu mengembalikan false jika argumennya obj bukan nilai Single . Contoh berikut mengilustrasikan perbedaan perilaku antara dua metode kelebihan beban. Dalam kasus semua jenis numerik primitif kecuali di Double Visual Basic dan kecuali untuk Decimal dan Double dalam C#, perbandingan pertama kembali true karena pengompilasi secara otomatis melakukan konversi pelebaran dan memanggil Equals(Single) metode , sedangkan perbandingan kedua kembali false karena kompilator memanggil Equals(Object) metode .

using System;

public class Example
{
   static float value = 112;
   
   public static void Main()
   {
      byte byte1= 112;
      Console.WriteLine("value = byte1: {0,16}", value.Equals(byte1));
      TestObjectForEquality(byte1);

      short short1 = 112;
      Console.WriteLine("value = short1: {0,16}", value.Equals(short1));
      TestObjectForEquality(short1);

      int int1 = 112;
      Console.WriteLine("value = int1: {0,18}", value.Equals(int1));
      TestObjectForEquality(int1);

      long long1 = 112;
      Console.WriteLine("value = long1: {0,17}", value.Equals(long1));
      TestObjectForEquality(long1);
      
      sbyte sbyte1 = 112;
      Console.WriteLine("value = sbyte1: {0,16}", value.Equals(sbyte1));
      TestObjectForEquality(sbyte1);

      ushort ushort1 = 112;
      Console.WriteLine("value = ushort1: {0,16}", value.Equals(ushort1));
      TestObjectForEquality(ushort1);

      uint uint1 = 112;
      Console.WriteLine("value = uint1: {0,18}", value.Equals(uint1));
      TestObjectForEquality(uint1);

      ulong ulong1 = 112;
      Console.WriteLine("value = ulong1: {0,17}", value.Equals(ulong1));
      TestObjectForEquality(ulong1);
      
      decimal dec1 = 112m;
      Console.WriteLine("value = dec1: {0,21}", value.Equals(dec1));
      TestObjectForEquality(dec1);

      double dbl1 = 112;
      Console.WriteLine("value = dbl1: {0,20}", 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 (Single) = 112 (Byte): False
//
//       value = short1:             True
//       112 (Single) = 112 (Int16): False
//
//       value = int1:               True
//       112 (Single) = 112 (Int32): False
//
//       value = long1:              True
//       112 (Single) = 112 (Int64): False
//
//       value = sbyte1:             True
//       112 (Single) = 112 (SByte): False
//
//       value = ushort1:             True
//       112 (Single) = 112 (UInt16): False
//
//       value = uint1:               True
//       112 (Single) = 112 (UInt32): False
//
//       value = ulong1:              True
//       112 (Single) = 112 (UInt64): False
//
//       value = dec1:                 False
//       112 (Single) = 112 (Decimal): False
//
//       value = dbl1:                False
//       112 (Single) = 112 (Double): False

let value = 112f

let testObjectForEquality (obj: obj) =
    printfn $"{value} ({value.GetType().Name}) = {obj} ({obj.GetType().Name}): {value.Equals obj}\n"

[<EntryPoint>]
let main _ =
    let byte1= 112uy
    printfn $"value = byte1: {value.Equals byte1,16}"
    testObjectForEquality byte1

    let short1 = 112s
    printfn $"value = short1: {value.Equals short1,16}"
    testObjectForEquality short1

    let int1 = 112
    printfn $"value = int1: {value.Equals int1,18}"
    testObjectForEquality int1

    let long1 = 112L
    printfn $"value = long1: {value.Equals long1,17}"
    testObjectForEquality long1
    
    let sbyte1 = 112y
    printfn $"value = sbyte1: {value.Equals sbyte1,16}"
    testObjectForEquality sbyte1

    let ushort1 = 112us
    printfn $"value = ushort1: {value.Equals ushort1,16}"
    testObjectForEquality ushort1

    let uint1 = 112u
    printfn $"value = uint1: {value.Equals uint1,18}"
    testObjectForEquality uint1

    let ulong1 = 112uL
    printfn $"value = ulong1: {value.Equals ulong1,17}"
    testObjectForEquality ulong1
    
    let dec1 = 112m
    printfn $"value = dec1: {value.Equals dec1,21}"
    testObjectForEquality dec1

    let dbl1 = 112.
    printfn $"value = dbl1: {value.Equals dbl1,20}"
    testObjectForEquality dbl1
    0

// The example displays the following output:
//       value = byte1:             True
//       112 (Single) = 112 (Byte): False
//
//       value = short1:             True
//       112 (Single) = 112 (Int16): False
//
//       value = int1:               True
//       112 (Single) = 112 (Int32): False
//
//       value = long1:              True
//       112 (Single) = 112 (Int64): False
//
//       value = sbyte1:             True
//       112 (Single) = 112 (SByte): False
//
//       value = ushort1:             True
//       112 (Single) = 112 (UInt16): False
//
//       value = uint1:               True
//       112 (Single) = 112 (UInt32): False
//
//       value = ulong1:              True
//       112 (Single) = 112 (UInt64): False
//
//       value = dec1:                 False
//       112 (Single) = 112 (Decimal): False
//
//       value = dbl1:                False
//       112 (Single) = 112 (Double): False

Module Example
   Dim value As Single = 112
   
   Public Sub Main()
      Dim byte1 As Byte = 112
      Console.WriteLine("value = byte1: {0,16}", value.Equals(byte1))
      TestObjectForEquality(byte1)
      
      Dim short1 As Short = 112
      Console.WriteLine("value = short1: {0,16}", value.Equals(short1))
      TestObjectForEquality(short1)

      Dim int1 As Integer = 112
      Console.WriteLine("value = int1: {0,18}", value.Equals(int1))
      TestObjectForEquality(int1)

      Dim long1 As Long = 112
      Console.WriteLine("value = long1: {0,17}", value.Equals(long1))
      TestObjectForEquality(long1)

      Dim sbyte1 As SByte = 112
      Console.WriteLine("value = sbyte1: {0,16}", value.Equals(sbyte1))
      TestObjectForEquality(sbyte1)
      
      Dim ushort1 As UShort = 112
      Console.WriteLine("value = ushort1: {0,16}", value.Equals(ushort1))
      TestObjectForEquality(ushort1)

      Dim uint1 As UInteger = 112
      Console.WriteLine("value = uint1: {0,18}", value.Equals(uint1))
      TestObjectForEquality(uint1)

      Dim ulong1 As ULong = 112
      Console.WriteLine("value = ulong1: {0,17}", value.Equals(ulong1))
      TestObjectForEquality(ulong1)
      
      Dim dec1 As Decimal = 112d
      Console.WriteLine("value = dec1: {0,20}", value.Equals(dec1))
      TestObjectForEquality(dec1)

      Dim dbl1 As Double = 112
      Console.WriteLine("value = dbl1: {0,20}", 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 (Single) = 112 (Byte): False
'
'       value = short1:             True
'       112 (Single) = 112 (Int16): False
'
'       value = int1:               True
'       112 (Single) = 112 (Int32): False
'
'       value = long1:              True
'       112 (Single) = 112 (Int64): False
'
'       value = sbyte1:             True
'       112 (Single) = 112 (SByte): False
'
'       value = ushort1:             True
'       112 (Single) = 112 (UInt16): False
'
'       value = uint1:               True
'       112 (Single) = 112 (UInt32): False
'
'       value = ulong1:              True
'       112 (Single) = 112 (UInt64): False
'
'       value = dec1:                 True
'       112 (Single) = 112 (Decimal): False
'
'       value = dbl1:                False
'       112 (Single) = 112 (Double): False

Lihat juga

CompareTo(Object)

Berlaku untuk

Equals(Single)

Sumber:: Single.cs

Sumber:: Single.cs

Sumber:: Single.cs

Mengembalikan nilai yang menunjukkan apakah instans ini dan objek tertentu Single mewakili nilai yang sama.

public:
 virtual bool Equals(float obj);

public bool Equals (float obj);

override this.Equals : single -> bool

Public Function Equals (obj As Single) As Boolean

Parameter

obj: Single

Objek untuk dibandingkan dengan instans ini.

Mengembalikan

Boolean

true jika obj sama dengan instans ini; jika tidak, false.

Penerapan

Equals(T)

Keterangan

Untuk informasi selengkapnya tentang API ini, lihat Keterangan API Tambahan untuk Single.Equals.

Catatan Bagi Pemanggil

using System;

public class Example
{
   static float value = 112;
   
   public static void Main()
   {
      byte byte1= 112;
      Console.WriteLine("value = byte1: {0,16}", value.Equals(byte1));
      TestObjectForEquality(byte1);

      short short1 = 112;
      Console.WriteLine("value = short1: {0,16}", value.Equals(short1));
      TestObjectForEquality(short1);

      int int1 = 112;
      Console.WriteLine("value = int1: {0,18}", value.Equals(int1));
      TestObjectForEquality(int1);

      long long1 = 112;
      Console.WriteLine("value = long1: {0,17}", value.Equals(long1));
      TestObjectForEquality(long1);
      
      sbyte sbyte1 = 112;
      Console.WriteLine("value = sbyte1: {0,16}", value.Equals(sbyte1));
      TestObjectForEquality(sbyte1);

      ushort ushort1 = 112;
      Console.WriteLine("value = ushort1: {0,16}", value.Equals(ushort1));
      TestObjectForEquality(ushort1);

      uint uint1 = 112;
      Console.WriteLine("value = uint1: {0,18}", value.Equals(uint1));
      TestObjectForEquality(uint1);

      ulong ulong1 = 112;
      Console.WriteLine("value = ulong1: {0,17}", value.Equals(ulong1));
      TestObjectForEquality(ulong1);
      
      decimal dec1 = 112m;
      Console.WriteLine("value = dec1: {0,21}", value.Equals(dec1));
      TestObjectForEquality(dec1);

      double dbl1 = 112;
      Console.WriteLine("value = dbl1: {0,20}", 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 (Single) = 112 (Byte): False
//
//       value = short1:             True
//       112 (Single) = 112 (Int16): False
//
//       value = int1:               True
//       112 (Single) = 112 (Int32): False
//
//       value = long1:              True
//       112 (Single) = 112 (Int64): False
//
//       value = sbyte1:             True
//       112 (Single) = 112 (SByte): False
//
//       value = ushort1:             True
//       112 (Single) = 112 (UInt16): False
//
//       value = uint1:               True
//       112 (Single) = 112 (UInt32): False
//
//       value = ulong1:              True
//       112 (Single) = 112 (UInt64): False
//
//       value = dec1:                 False
//       112 (Single) = 112 (Decimal): False
//
//       value = dbl1:                False
//       112 (Single) = 112 (Double): False

let value = 112f

let testObjectForEquality (obj: obj) =
    printfn $"{value} ({value.GetType().Name}) = {obj} ({obj.GetType().Name}): {value.Equals obj}\n"

[<EntryPoint>]
let main _ =
    let byte1= 112uy
    printfn $"value = byte1: {value.Equals byte1,16}"
    testObjectForEquality byte1

    let short1 = 112s
    printfn $"value = short1: {value.Equals short1,16}"
    testObjectForEquality short1

    let int1 = 112
    printfn $"value = int1: {value.Equals int1,18}"
    testObjectForEquality int1

    let long1 = 112L
    printfn $"value = long1: {value.Equals long1,17}"
    testObjectForEquality long1
    
    let sbyte1 = 112y
    printfn $"value = sbyte1: {value.Equals sbyte1,16}"
    testObjectForEquality sbyte1

    let ushort1 = 112us
    printfn $"value = ushort1: {value.Equals ushort1,16}"
    testObjectForEquality ushort1

    let uint1 = 112u
    printfn $"value = uint1: {value.Equals uint1,18}"
    testObjectForEquality uint1

    let ulong1 = 112uL
    printfn $"value = ulong1: {value.Equals ulong1,17}"
    testObjectForEquality ulong1
    
    let dec1 = 112m
    printfn $"value = dec1: {value.Equals dec1,21}"
    testObjectForEquality dec1

    let dbl1 = 112.
    printfn $"value = dbl1: {value.Equals dbl1,20}"
    testObjectForEquality dbl1
    0

// The example displays the following output:
//       value = byte1:             True
//       112 (Single) = 112 (Byte): False
//
//       value = short1:             True
//       112 (Single) = 112 (Int16): False
//
//       value = int1:               True
//       112 (Single) = 112 (Int32): False
//
//       value = long1:              True
//       112 (Single) = 112 (Int64): False
//
//       value = sbyte1:             True
//       112 (Single) = 112 (SByte): False
//
//       value = ushort1:             True
//       112 (Single) = 112 (UInt16): False
//
//       value = uint1:               True
//       112 (Single) = 112 (UInt32): False
//
//       value = ulong1:              True
//       112 (Single) = 112 (UInt64): False
//
//       value = dec1:                 False
//       112 (Single) = 112 (Decimal): False
//
//       value = dbl1:                False
//       112 (Single) = 112 (Double): False

Module Example
   Dim value As Single = 112
   
   Public Sub Main()
      Dim byte1 As Byte = 112
      Console.WriteLine("value = byte1: {0,16}", value.Equals(byte1))
      TestObjectForEquality(byte1)
      
      Dim short1 As Short = 112
      Console.WriteLine("value = short1: {0,16}", value.Equals(short1))
      TestObjectForEquality(short1)

      Dim int1 As Integer = 112
      Console.WriteLine("value = int1: {0,18}", value.Equals(int1))
      TestObjectForEquality(int1)

      Dim long1 As Long = 112
      Console.WriteLine("value = long1: {0,17}", value.Equals(long1))
      TestObjectForEquality(long1)

      Dim sbyte1 As SByte = 112
      Console.WriteLine("value = sbyte1: {0,16}", value.Equals(sbyte1))
      TestObjectForEquality(sbyte1)
      
      Dim ushort1 As UShort = 112
      Console.WriteLine("value = ushort1: {0,16}", value.Equals(ushort1))
      TestObjectForEquality(ushort1)

      Dim uint1 As UInteger = 112
      Console.WriteLine("value = uint1: {0,18}", value.Equals(uint1))
      TestObjectForEquality(uint1)

      Dim ulong1 As ULong = 112
      Console.WriteLine("value = ulong1: {0,17}", value.Equals(ulong1))
      TestObjectForEquality(ulong1)
      
      Dim dec1 As Decimal = 112d
      Console.WriteLine("value = dec1: {0,20}", value.Equals(dec1))
      TestObjectForEquality(dec1)

      Dim dbl1 As Double = 112
      Console.WriteLine("value = dbl1: {0,20}", 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 (Single) = 112 (Byte): False
'
'       value = short1:             True
'       112 (Single) = 112 (Int16): False
'
'       value = int1:               True
'       112 (Single) = 112 (Int32): False
'
'       value = long1:              True
'       112 (Single) = 112 (Int64): False
'
'       value = sbyte1:             True
'       112 (Single) = 112 (SByte): False
'
'       value = ushort1:             True
'       112 (Single) = 112 (UInt16): False
'
'       value = uint1:               True
'       112 (Single) = 112 (UInt32): False
'
'       value = ulong1:              True
'       112 (Single) = 112 (UInt64): False
'
'       value = dec1:                 True
'       112 (Single) = 112 (Decimal): False
'
'       value = dbl1:                False
'       112 (Single) = 112 (Double): False

Lihat juga

Berlaku untuk

Single.Equals Metode

Definisi

Overload

Equals(Object)

Parameter

Mengembalikan

Contoh

Keterangan

Catatan Bagi Pemanggil

Lihat juga

Berlaku untuk

Equals(Single)

Parameter

Mengembalikan

Penerapan

Keterangan

Catatan Bagi Pemanggil

Lihat juga

Berlaku untuk

Saran dan Komentar

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