String.Inequality(String, String) 運算子

定義

命名空間:

System

組件:

System.Runtime.dll

Source:

String.Comparison.cs

判斷兩個指定的字串是否具有不同的值。

public:
 static bool operator !=(System::String ^ a, System::String ^ b);

public static bool operator != (string? a, string? b);

static member op_Inequality : string * string -> bool

Public Shared Operator != (a As String, b As String) As Boolean

參數

a

String

要比較的第一個字串，或是 null。

b

String

要比較的第二個字串，或 null。

傳回

Boolean

如果 true 的值與 a 的值不同，則為 b，否則為 false。

範例

下列範例示範不等比較運算子。

// Example for the String Inequality operator.
using namespace System;
void CompareAndDisplay( String^ Comparand )
{
   String^ Lower = "abcd";
   Console::WriteLine( "\"{0}\" != \"{1}\" ?  {2}", Lower, Comparand, Lower != Comparand );
}

int main()
{
   Console::WriteLine( "This example of the String Inequality operator\n"
   "generates the following output.\n" );
   CompareAndDisplay( "ijkl" );
   CompareAndDisplay( "ABCD" );
   CompareAndDisplay( "abcd" );
}

/*
This example of the String Inequality operator
generates the following output.

"abcd" != "ijkl" ?  True
"abcd" != "ABCD" ?  True
"abcd" != "abcd" ?  False
*/

// Example for the String Inequality operator.
using System;

class InequalityOp 
{
    public static void Main() 
    {
        Console.WriteLine( 
            "This example of the String Inequality operator\n" +
            "generates the following output.\n" );

        CompareAndDisplay( "ijkl" );
        CompareAndDisplay( "ABCD" );
        CompareAndDisplay( "abcd" );
    }

    static void CompareAndDisplay( String Comparand )
    {
        String  Lower = "abcd";

        Console.WriteLine( 
            "\"{0}\" != \"{1}\" ?  {2}",
            Lower, Comparand, Lower != Comparand );
    }
}

/*
This example of the String Inequality operator
generates the following output.

"abcd" != "ijkl" ?  True
"abcd" != "ABCD" ?  True
"abcd" != "abcd" ?  False
*/

// Example for the String Inequality operator.
printfn "This example of the String Inequality operator\ngenerates the following output.\n"

let compareAndDisplay comparand =
    let lower = "abcd"
    printfn $"\"%s{lower}\" <> \"%s{comparand}\" ?  {lower <> comparand}"

compareAndDisplay "ijkl"
compareAndDisplay "ABCD"
compareAndDisplay "abcd"

(*
This example of the String Inequality operator
generates the following output.

"abcd" <> "ijkl" ?  True
"abcd" <> "ABCD" ?  True
"abcd" <> "abcd" ?  False
*)

備註

方法 Inequality 會定義 類別的不等比較運算子 String 運算。 它會啟用程式碼，例如 [範例] 區段中所示的程式碼。

運算子 Inequality 接著會呼叫靜態 Equals(String, String) 方法，它會執行區分大小寫且不區分文化特性的序數 () 比較。

注意

Visual Basic 編譯器不會將不等比較運算子解析為方法的 Inequality 呼叫。 相反地，不等比較運算子會包裝方法的 Operators.CompareString 呼叫。