String.Length 属性

定义

命名空间:

System

程序集:

System.Runtime.dll

Source:

String.cs

获取当前 String 对象中的字符数。

public:
 property int Length { int get(); };

public int Length { get; }

member this.Length : int

Public ReadOnly Property Length As Integer

属性值

Int32

当前字符串中字符的数量。

示例

以下示例演示 属性 Length 。

// Sample for String::Length
using namespace System;
int main()
{
   String^ str = "abcdefg";
   Console::WriteLine( "1) The length of '{0}' is {1}", str, str->Length );
   Console::WriteLine( "2) The length of '{0}' is {1}", "xyz", ((String^)"xyz")->Length );
   int length = str->Length;
   Console::WriteLine( "1) The length of '{0}' is {1}", str, length );
}

/*
This example displays the following output:
   1) The length of 'abcdefg' is 7
   2) The length of 'xyz' is 3
   3) The length of 'abcdefg' is 7
*/

string str = "abcdefg";
Console.WriteLine("1) The length of '{0}' is {1}", str, str.Length);
Console.WriteLine("2) The length of '{0}' is {1}", "xyz", "xyz".Length);

int length = str.Length;
Console.WriteLine("3) The length of '{0}' is {1}", str, length);

// This example displays the following output:
//    1) The length of 'abcdefg' is 7
//    2) The length of 'xyz' is 3
//    3) The length of 'abcdefg' is 7

let str = "abcdefg"
printfn $"1) The length of '{str}' is {str.Length}"
printfn $"""2) The length of '{"xyz"}' is {"xyz".Length}"""

let length = str.Length
printfn $"3) The length of '{str}' is {length}"

// This example displays the following output:
//    1) The length of 'abcdefg' is 7
//    2) The length of 'xyz' is 3
//    3) The length of 'abcdefg' is 7

Class Sample
   Public Shared Sub Main()
      Dim str As String = "abcdefg"
      Console.WriteLine("1) The length of '{0}' is {1}", str, str.Length)
      Console.WriteLine("2) The length of '{0}' is {1}", "xyz", "xyz".Length)
      Dim length As Integer = str.Length
      Console.WriteLine("1) The length of '{0}' is {1}", str, length)
   End Sub
End Class
'
'This example displays the following output:
'    1) The length of 'abcdefg' is 7
'    2) The length of 'xyz' is 3
'    3) The length of 'abcdefg' is 7

注解

属性 Length 返回此实例中的对象数 Char ，而不是 Unicode 字符数。 原因是 Unicode 字符可能由多个 Char表示。 System.Globalization.StringInfo使用 类来处理每个 Unicode 字符，而不是每个 Char。

在某些语言（如 C 和 C++）中，null 字符表示字符串的结尾。 在 .NET 中，null 字符可以嵌入到字符串中。 当字符串包含一个或多个 null 字符时，它们包含在总字符串的长度中。 例如，在下面的字符串中，子字符串“abc”和“def”用空字符分隔。 属性 Length 返回 7，指示它包含六个字母字符以及 null 字符。

using namespace System;
using namespace System::Text;

void main()
{
   String^ characters = "abc" + L'0' + "def";
   Console::WriteLine(characters->Length);        // Displays 7
}

string characters = "abc\u0000def";
Console.WriteLine(characters.Length); // Displays 7

let characters = "abc\u0000def"
printfn $"{characters.Length}" // Displays 7

Imports System.Text

Module Example

   Public Sub Main()
      Dim characters As String = "abc" + ChrW(0) + "def"
      Console.WriteLine(characters.Length)       ' Displays 7
   End Sub
End Module

另请参阅

• Int32