Char.CompareTo 方法
定義
重要
部分資訊涉及發行前產品，在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊，不做任何明確或隱含的瑕疵擔保。
將此實例與指定的物件或值類型比較，並指示該實例是否在排序順序中與指定的物件或值類型相鄰、之後或出現的位置相同。
多載
| 名稱 | Description |
|---|---|
| CompareTo(Char) | |
| CompareTo(Object) |
將此實例與指定物件比較，並指示該實例是否在排序順序中與指定 Object物件之前、之後或出現於相同位置。 |
CompareTo(Char)
- 來源:
- Char.cs
- 來源:
- Char.cs
- 來源:
- Char.cs
- 來源:
- Char.cs
- 來源:
- Char.cs
public:
virtual int CompareTo(char value);public int CompareTo(char value);abstract member CompareTo : char -> int
override this.CompareTo : char -> intPublic Function CompareTo (value As Char) As Integer參數
傳回
一個帶符號的數字，表示該實例在排序順序中相對於參數 value 的位置。
| 回報價值 | 描述 |
|---|---|
| 低於零 | 此實例發生 value於 之前。
|
| 零 | 此實例在排序 value順序中與 位置相同。
|
| 大於零 | 此實例可得 value。
|
實作
範例
以下程式碼範例展示了該方法在多種值與參考類型下的通用與非通用版本 CompareTo 。
// 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
'
備註
這個方法會實作 System.IComparable<T> 介面並執行比 Char.CompareTo 方法稍微好一點，因為它不需要將 參數轉換成 value 物件。
此方法所進行的比較基於該實例與 value的編碼值，而非其字典序特性。
如果 CompareTo 方法參數型別的位元數比實例型別更窄，有些程式語言會進行隱式擴展轉換，將參數值轉換成位元數較多的值。
例如，假設實體類型為 Int32 ，且參數類型為 Byte。 Microsoft C# 編譯器會產生指令，將參數值表示為 Int32 物件，然後產生一個 Int32.CompareTo 方法，比較 Int32 實例與 Int32 參數表示的值。
通常，隱式擴寬轉換會對數值型態進行。 請查閱你程式語言的文件，判斷其編譯器是否執行寬度轉換。 若實例與參數類型不符且無法取得合適的轉換，編譯器會產生指令將參數框定並呼叫 CompareTo 過載以取得參數 Object 。
另請參閱
適用於
CompareTo(Object)
- 來源:
- Char.cs
- 來源:
- Char.cs
- 來源:
- Char.cs
- 來源:
- Char.cs
- 來源:
- Char.cs
將此實例與指定物件比較，並指示該實例是否在排序順序中與指定 Object物件之前、之後或出現於相同位置。
public:
virtual int CompareTo(System::Object ^ value);public int CompareTo(object? value);abstract member CompareTo : obj -> int
override this.CompareTo : obj -> intPublic Function CompareTo (value As Object) As Integer參數
- value
- Object
一個物件可將此實例與 比較，或 null。
傳回
一個帶符號的數字，表示該實例在排序順序中相對於參數 value 的位置。
| 回報價值 | 描述 |
|---|---|
| 低於零 | 此實例發生 value於 之前。
|
| 零 | 此實例在排序 value順序中與 位置相同。
|
| 大於零 | 此實例可得 value。
-或-
|
實作
例外狀況
value 不是 Char 物件。
範例
以下程式碼範例示範 CompareTo。
using System;
public class CompareToSample {
public static void Main() {
char chA = 'A';
char chB = 'B';
Console.WriteLine(chA.CompareTo('A')); // Output: "0" (meaning they're equal)
Console.WriteLine('b'.CompareTo(chB)); // Output: "32" (meaning 'b' is greater than 'B' by 32)
Console.WriteLine(chA.CompareTo(chB)); // Output: "-1" (meaning 'A' is less than 'B' by 1)
}
}
let chA = 'A'
let chB = 'B'
printfn $"{chA.CompareTo 'A'}" // Output: "0" (meaning they're equal)
printfn $"{'b'.CompareTo chB}" // Output: "32" (meaning 'b' is greater than 'B' by 32)
printfn $"{chA.CompareTo chB}" // Output: "-1" (meaning 'A' is less than 'B' by 1)
Module CompareToSample
Sub Main()
Dim chA As Char
chA = "A"c
Dim chB As Char
chB = "B"c
Console.WriteLine(chA.CompareTo("A"c)) ' Output: "0" (meaning they're equal)
Console.WriteLine("b"c.CompareTo(chB)) ' Output: "32" (meaning 'b' is 32 greater than 'B')
Console.WriteLine(chA.CompareTo(chB)) ' Output: "-1" (meaning 'A' is less than 'B' by 1)
End Sub
End Module
備註
此 CompareTo 方法實作介面 IComparable 。
value 參數必須是 null 或 Char的實例;否則會擲回例外狀況。
此方法的比較基於該實例與 value的編碼值，而不一定是其字典序特徵。 不論其值為何，Char的任何實例都會被視為大於 null。
