String.CompareTo 方法

定义

将此实例与指定对象或 String 进行比较,并返回一个整数,该整数指示此实例在排序顺序中是位于指定对象或 String 之前、之后还是与其出现在同一位置。

重载

CompareTo(String)

将此实例与指定的 String 对象进行比较,并指示此实例在排序顺序中是位于指定的字符串之前、之后还是与其出现在同一位置。

CompareTo(Object)

将此实例与指定的 Object 进行比较,并指示此实例在排序顺序中是位于指定的 Object 之前、之后还是与其出现在同一位置。

注解

该方法的两个 CompareTo 重载都执行区分区域性和区分大小写的比较。 不能使用此方法执行不区分区域性的序号比较。 为便于代码清楚起见,建议避免使用 CompareTo 该方法并改为调用该方法 Compare

CompareTo(String)

将此实例与指定的 String 对象进行比较,并指示此实例在排序顺序中是位于指定的字符串之前、之后还是与其出现在同一位置。

public:
 virtual int CompareTo(System::String ^ strB);
public:
 int CompareTo(System::String ^ strB);
public int CompareTo (string strB);
public int CompareTo (string? strB);
abstract member CompareTo : string -> int
override this.CompareTo : string -> int
member this.CompareTo : string -> int
Public Function CompareTo (strB As String) As Integer

参数

strB
String

要与此实例进行比较的字符串。

返回

Int32

一个 32 位带符号整数,该整数指示此实例在排序顺序中是位于 strB 参数之前、之后还是与其出现在同一位置。

“值” 条件
小于零 此实例位于 strB 之前。
此实例在排序顺序中的位置与 strB 相同。
大于零 此实例位于 strB 之后。
  • 或 -

strB 上声明的默认值为 null

实现

示例

以下示例使用 CompareTo 此方法将当前字符串实例与其他字符串进行比较。

using namespace System;

String^ CompareStrings(String^ str1, String^ str2)
{
   // compare the values, using the CompareTo method on the first string
   int cmpVal = str1->CompareTo(str2);
   if (cmpVal == 0)
      // the values are the same
      return "The strings occur in the same position in the sort order.";
   else if (cmpVal < 0)
      return "The first string precedes the second in the sort order.";
   else
      return "The first string follows the second in the sort order.";
}

int main()
{
   String^ strFirst = "Goodbye";
   String^ strSecond = "Hello";
   String^ strThird = "a small String*";
   String^ strFourth = "goodbye";
   
   // Compare a string to itself.
   Console::WriteLine(CompareStrings(strFirst, strFirst));
   Console::WriteLine(CompareStrings(strFirst, strSecond));
   Console::WriteLine(CompareStrings(strFirst, strThird));
   
   // Compare a string to another string that varies only by case.
   Console::WriteLine(CompareStrings(strFirst, strFourth));
   Console::WriteLine(CompareStrings(strFourth, strFirst));
}
// The example displays the following output:
//       The strings occur in the same position in the sort order.
//       The first string precedes the second in the sort order.
//       The first string follows the second in the sort order.
//       The first string follows the second in the sort order.
//       The first string precedes the second in the sort order.
using System;

public class Example
{
   public static void Main()
   {
      string strFirst = "Goodbye";
      string strSecond = "Hello";
      string strThird = "a small string";
      string strFourth = "goodbye";

      // Compare a string to itself.
      Console.WriteLine(CompareStrings(strFirst, strFirst));

      Console.WriteLine(CompareStrings(strFirst, strSecond));
      Console.WriteLine(CompareStrings(strFirst, strThird));

      // Compare a string to another string that varies only by case.
      Console.WriteLine(CompareStrings(strFirst, strFourth));
      Console.WriteLine(CompareStrings(strFourth, strFirst));
   }

   private static string CompareStrings( string str1, string str2 )
   {
      // Compare the values, using the CompareTo method on the first string.
      int cmpVal = str1.CompareTo(str2);

       if (cmpVal == 0) // The strings are the same.
         return "The strings occur in the same position in the sort order.";
      else if (cmpVal < 0)
         return "The first string precedes the second in the sort order.";
      else
         return "The first string follows the second in the sort order.";
    }
}
// The example displays the following output:
//       The strings occur in the same position in the sort order.
//       The first string precedes the second in the sort order.
//       The first string follows the second in the sort order.
//       The first string follows the second in the sort order.
//       The first string precedes the second in the sort order.
let strFirst = "Goodbye"
let strSecond = "Hello"
let strThird = "a small string"
let strFourth = "goodbye"

let compareStrings (str1: string) str2 =
    // Compare the values, using the CompareTo method on the first string.
    match str1.CompareTo str2 with
    | 0 -> // The strings are the same.
        "The strings occur in the same position in the sort order."
    | x when x < 0 ->
        "The first string precedes the second in the sort order."
    | _ ->
        "The first string follows the second in the sort order."

// Compare a string to itself.
printfn $"{compareStrings strFirst strFirst}"

printfn $"{compareStrings strFirst strSecond}"
printfn $"{compareStrings strFirst strThird}"

// Compare a string to another string that varies only by case.
printfn $"{compareStrings strFirst strFourth}"
printfn $"{compareStrings strFourth strFirst}"

// The example displays the following output:
//       The strings occur in the same position in the sort order.
//       The first string precedes the second in the sort order.
//       The first string follows the second in the sort order.
//       The first string follows the second in the sort order.
//       The first string precedes the second in the sort order.
Public Module Example
   Public Sub Main()
      Dim strFirst As String = "Goodbye"
      Dim strSecond As String = "Hello"
      Dim strThird As String = "a small string"
      Dim strFourth As String = "goodbye"

      ' Compare a string to itself.
      Console.WriteLine(CompareStrings(strFirst, strFirst))
        
      Console.WriteLine(CompareStrings(strFirst, strSecond))
      Console.WriteLine(CompareStrings(strFirst, strThird))
        
      ' Compare a string to another string that varies only by case.
      Console.WriteLine(CompareStrings(strFirst, strFourth))
      Console.WriteLine(CompareStrings(strFourth, strFirst))
   End Sub
    
   Private Function CompareStrings(str1 As String, str2 As String) As String
      Dim cmpVal As Integer = str1.CompareTo(str2)
      If cmpVal = 0 Then
         ' The values are the same.
         Return "The strings occur in the same position in the sort order."
      ElseIf cmpVal < 0 Then
         Return "The first string precedes the second in the sort order."
      Else
         Return "The first string follows the second in the sort order."
      End If
   End Function
End Module
' This example displays the following output:
'       The strings occur in the same position in the sort order.
'       The strings occur in the same position in the sort order.
'       The first string precedes the second in the sort order.
'       The first string follows the second in the sort order.
'       The first string follows the second in the sort order.
'       The first string precedes the second in the sort order.

以下示例演示了多个值和引用类型的 CompareTo 方法的泛型和非泛型版本。

// 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.
open System

let show caption (var1: obj) (var2: obj) resultGeneric resultNonGeneric =
    printf "%s" caption
    if resultGeneric = resultNonGeneric then
        let relation =
            if resultGeneric < 0 then "less than"
            elif resultGeneric > 0 then "greater than"
            else "equal to"
        printfn $"{var1} is {relation} {var2}"

    // The following condition will never occur because the generic and non-generic
    // CompareTo methods are equivalent.
    else
        printfn $"Generic CompareTo = {resultGeneric} non-generic CompareTo = {resultNonGeneric}"

let now = DateTime.Now
// Time span = 11 days, 22 hours, 33 minutes, 44 seconds
let tsX = TimeSpan(11, 22, 33, 44)
// Version = 1.2.333.4
let versX = Version "1.2.333.4"
// Guid = CA761232-ED42-11CE-BACD-00AA0057B223
let guidX = Guid "{CA761232-ED42-11CE-BACD-00AA0057B223}"

let a1, a2 = true, true
let b1, b2 = 1uy, 1uy
let c1, c2 = -2s, 2s
let d1, d2 = 3, 3
let e1, e2 = 4L, -4L
let f1, f2 = -5.5m, 5.5m
let g1, g2 = 6.6f, 6.6f
let h1, h2 = 7.7, -7.7
let i1, i2 = 'A', 'A'
let j1, j2 = "abc", "abc"
let k1, k2 = now, now
let l1, l2 = tsX, tsX
let m1, m2 = versX, Version "2.0"
let n1, n2 = guidX, guidX

// The following types are not CLS-compliant.
let w1, w2 = 8y, 8y
let x1, x2 = 9us, 9us
let y1, y2 = 10u, 10u
let z1, z2 = 11uL, 11uL

printfn "\nThe following is the result of using the generic and non-generic\nversions of the CompareTo method for several base types:\n"
try
    // The second and third show function call parameters are automatically boxed because
    // the second and third show function declaration arguments expect type Object.
    show "Boolean:  " a1 a2 (a1.CompareTo a2) (a1.CompareTo (a2 :> obj))

    show "Byte:     " b1 b2 (b1.CompareTo b2) (b1.CompareTo (b2 :> obj))
    show "Int16:    " c1 c2 (c1.CompareTo c2) (c1.CompareTo (c2 :> obj))
    show "Int32:    " d1 d2 (d1.CompareTo d2) (d1.CompareTo (d2 :> obj))
    show "Int64:    " e1 e2 (e1.CompareTo e2) (e1.CompareTo (e2 :> obj))
    show "Decimal:  " f1 f2 (f1.CompareTo f2) (f1.CompareTo (f2 :> obj))
    show "Single:   " g1 g2 (g1.CompareTo g2) (g1.CompareTo (g2 :> obj))
    show "Double:   " h1 h2 (h1.CompareTo h2) (h1.CompareTo (h2 :> obj))
    show "Char:     " i1 i2 (i1.CompareTo i2) (i1.CompareTo (i2 :> obj))
    show "String:   " j1 j2 (j1.CompareTo j2) (j1.CompareTo (j2 :> obj))
    show "DateTime: " k1 k2 (k1.CompareTo k2) (k1.CompareTo (k2 :> obj))
    show "TimeSpan: " l1 l2 (l1.CompareTo l2) (l1.CompareTo (l2 :> obj))
    show "Version:  " m1 m2 (m1.CompareTo m2) (m1.CompareTo (m2 :> obj))
    show "Guid:     " n1 n2 (n1.CompareTo n2) (n1.CompareTo (n2 :> obj))

    printfn "\nThe following types are not CLS-compliant:"
    show "SByte:    " w1 w2 (w1.CompareTo w2) (w1.CompareTo (w2 :> obj))
    show "UInt16:   " x1 x2 (x1.CompareTo x2) (x1.CompareTo (x2 :> obj))
    show "UInt32:   " y1 y2 (y1.CompareTo y2) (y1.CompareTo (y2 :> obj))
    show "UInt64:   " z1 z2 (z1.CompareTo z2) (z1.CompareTo (z2 :> obj))
with e -> printfn $"{e}"


// 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
'

注解

此方法使用当前区域性执行单词 (区分大小写和区分区域性) 比较。 有关单词、字符串和序号排序的详细信息,请参阅 System.Globalization.CompareOptions

注意

该方法 CompareTo 主要用于排序或字母顺序操作。 当方法调用的主要用途是确定两个字符串是否等效时,不应使用它。 若要确定两个字符串是否等效,请调用 Equals 该方法。

有关此方法的行为的详细信息,请参阅该方法的 Compare(String, String) “备注”部分。

此方法实现 System.IComparable<T> 接口并略高于 String.CompareTo(Object) 方法,因为它不必确定参数是否 strB 为必须装箱的可变值类型,并且不必将参数从某个 Object 参数强制转换为 a String

调用方说明

字符集包括可忽略字符。 此方法 CompareTo(String) 在执行区分区域性的比较时不考虑此类字符。 例如,如果以下代码在 .NET Framework 4 或更高版本上运行,则使用软连字符将“animal”与“ani-mal” (进行比较,或 U+00AD) 指示这两个字符串等效。

:::code language=“csharp” source=“~/snippets/csharp/System/String/CompareTo/compareto2.cs” id=“Snippet2”::::::code language=“fsharp” source=“~/snippets/fsharp/System/String/CompareTo/compareto2.fs” id=“Snippet2”:::code language=“vb” source=“~/snippets/visualbasic/VS_Snippets_CLR_System/system.string.compareto/vb/compareto2.vb” id=“Snippet2”:::

若要识别字符串比较中的可忽略字符,请调用 CompareOrdinal(String, String) 该方法。

另请参阅

适用于

CompareTo(Object)

将此实例与指定的 Object 进行比较,并指示此实例在排序顺序中是位于指定的 Object 之前、之后还是与其出现在同一位置。

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 -> int
Public Function CompareTo (value As Object) As Integer

参数

value
Object

一个对象,其计算结果为 String

返回

Int32

一个 32 位带符号整数,该整数指示此实例在排序顺序中是位于 value 参数之前、之后还是与其出现在同一位置。

“值” 条件
小于零 此实例位于 value 之前。
此实例在排序顺序中的位置与 value 相同。
大于零 此实例位于 value 之后。
  • 或 -

value 上声明的默认值为 null

实现

例外

value 不是 String

示例

以下示例将 CompareTo 该方法与一个 Object. 由于该方法尝试将实例与对象进行比较String,因此该方法将引发一个 ArgumentExceptionTestClass

using namespace System;

public ref class TestClass{};

int main()
{
   TestClass^ test = gcnew TestClass;
   array<Object^>^ objectsToCompare = { test, test->ToString(), 123,
                                        (123).ToString(), "some text",
                                        "Some Text" };
   String^ s = "some text";
   for each (Object^ objectToCompare in objectsToCompare) {
      try {
         Int32 i = s->CompareTo(objectToCompare);
         Console::WriteLine("Comparing '{0}' with '{1}': {2}",
                            s, objectToCompare, i);
      }
      catch (ArgumentException^ e) {
         Console::WriteLine("Bad argument: {0} (type {1})",
                            objectToCompare,
                            objectToCompare->GetType()->Name);
      }
   }
}
// The example displays the following output:
//    Bad argument: TestClass (type TestClass)
//    Comparing 'some text' with 'TestClass': -1
//    Bad argument: 123 (type Int32)
//    Comparing 'some text' with '123': 1
//    Comparing 'some text' with 'some text': 0
//    Comparing 'some text' with 'Some Text': -1
using System;

public class TestClass
{}

public class Example
{
   public static void Main()
   {
      var test = new TestClass();
      Object[] objectsToCompare = { test, test.ToString(), 123,
                                    123.ToString(), "some text",
                                    "Some Text" };
      string s = "some text";
      foreach (var objectToCompare in objectsToCompare) {
         try {
            int i = s.CompareTo(objectToCompare);
            Console.WriteLine("Comparing '{0}' with '{1}': {2}",
                              s, objectToCompare, i);
         }
         catch (ArgumentException) {
            Console.WriteLine("Bad argument: {0} (type {1})",
                              objectToCompare,
                              objectToCompare.GetType().Name);
         }
      }
   }
}
// The example displays the following output:
//    Bad argument: TestClass (type TestClass)
//    Comparing 'some text' with 'TestClass': -1
//    Bad argument: 123 (type Int32)
//    Comparing 'some text' with '123': 1
//    Comparing 'some text' with 'some text': 0
//    Comparing 'some text' with 'Some Text': -1
open System

type TestClass() = class end

let test = TestClass()
let objectsToCompare: obj list =
    [ test; string test; 123
      string 123; "some text"
      "Some Text" ]
let s = "some text"
for objectToCompare in objectsToCompare do
    try
        let i = s.CompareTo objectToCompare
        printfn $"Comparing '{s}' with '{objectToCompare}': {i}"
    with :? ArgumentException ->
        printfn $"Bad argument: {objectToCompare} (type {objectToCompare.GetType().Name})"
// The example displays the following output:
//    Bad argument: TestClass (type TestClass)
//    Comparing 'some text' with 'TestClass': -1
//    Bad argument: 123 (type Int32)
//    Comparing 'some text' with '123': 1
//    Comparing 'some text' with 'some text': 0
//    Comparing 'some text' with 'Some Text': -1
Public Class TestClass
End Class 


Public Class Example
   Public Shared Sub Main()
      Dim test As New TestClass()
      Dim objectsToCompare() As Object = { test, test.ToString(), 123,
                                           123.ToString(), "some text",
                                           "Some Text" }
      Dim s As String = "some text"
      For Each objectToCompare In objectsToCompare
         Try
            Dim i As Integer = s.CompareTo(objectToCompare)
            Console.WriteLine("Comparing '{0}' with '{1}': {2}",
                              s, objectToCompare, i)
         Catch e As ArgumentException
            Console.WriteLine("Bad argument: {0} (type {1})",
                              objectToCompare,
                              objectToCompare.GetType().Name)
         End Try
      Next
   End Sub 
End Class 
' The example displays the following output:
'       Bad argument: TestClass (type TestClass)
'       Comparing 'some text' with 'TestClass': -1
'       Bad argument: 123 (type Int32)
'       Comparing 'some text' with '123': 1
'       Comparing 'some text' with 'some text': 0
'       Comparing 'some text' with 'Some Text': -1

注解

value 必须是 String 对象。

注意

该方法 CompareTo 主要用于排序或字母顺序操作。 当方法调用的主要用途是确定两个字符串是否等效时,不应使用它。 若要确定两个字符串是否等效,请调用 Equals 该方法。

此方法使用当前区域性执行单词 (区分大小写和区分区域性) 比较。 有关单词、字符串和序号排序的详细信息,请参阅 System.Globalization.CompareOptions

有关此方法的行为的详细信息,请参阅该方法的 String.Compare(String, String) “备注”部分。

调用方说明

字符集包括可忽略字符。 此方法 CompareTo(Object) 在执行区分区域性的比较时不考虑此类字符。 例如,如果以下代码在 .NET Framework 4 或更高版本上运行,则使用软连字符将“animal”与“ani-mal” (进行比较,或 U+00AD) 表示这两个字符串等效。

:::code language=“csharp” source=“~/snippets/csharp/System/String/CompareTo/compareto1.cs” id=“Snippet1”::::::code language=“fsharp” source=“~/snippets/fsharp/System/String/CompareTo/compareto1.fs” id=“Snippet1”:code language=“vb” source=“~/snippets/visualbasic/VS_Snippets_CLR_System/system.string.compareto/vb/compareto1.vb” id=“Snippet1”::

若要识别字符串比较中的可忽略字符,请调用 CompareOrdinal(String, String) 该方法。

另请参阅

适用于