String.Equality(String, String) 操作员

定义

确定两个指定的字符串是否具有相同的值。Determines whether two specified strings have the same value.

public:
 static bool operator ==(System::String ^ a, System::String ^ b);
public static bool operator == (string a, string b);
static member ( = ) : string * string -> bool
Public Shared Operator == (a As String, b As String) As Boolean

参数

a
String

要比较的第一个字符串,或 nullThe first string to compare, or null.

b
String

要比较的第二个字符串,或 nullThe second string to compare, or null.

返回

如果 true 的值与 a 的值相同,则为 b;否则为 falsetrue if the value of a is the same as the value of b; otherwise, false.

示例

下面的示例演示了相等运算符。The following example demonstrates the equality operator.

// Example for the String Equality 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 Equality operator\n"
   "generates the following output.\n" );
   CompareAndDisplay( "ijkl" );
   CompareAndDisplay( "ABCD" );
   CompareAndDisplay( "abcd" );
}

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

"abcd" == "ijkl" ?  False
"abcd" == "ABCD" ?  False
"abcd" == "abcd" ?  True
*/
// Example for the String Equality operator.
using System;

class EqualityOp 
{
    public static void Main() 
    {
        Console.WriteLine( 
            "This example of the String Equality 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 Equality operator 
generates the following output.

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

注解

Equality 方法定义 String 类的相等运算符的运算。The Equality method defines the operation of the equality operator for the String class. 它将启用示例部分中所示的代码。It enables code such as that shown in the Example section. 运算符反过来调用静态 Equals(String, String) 方法,该方法执行序号(区分大小写和不区分区域性)比较。The operator, in turn, calls the static Equals(String, String) method, which performs an ordinal (case-sensitive and culture-insensitive) comparison.

备注

Visual Basic 编译器不会将相等运算符解析为对 Equality 方法的调用。The Visual Basic compiler does not resolve the equality operator as a call to the Equality method. 相反,相等运算符包装对 Operators.CompareString 方法的调用。Instead, the equality operator wraps a call to the Operators.CompareString method.

适用于