String.Concat 方法

定義

命名空間:

System

組件:

netstandard.dll, System.Runtime.dll

串接一個或多個 的 String實例，或 String 一個或多個實例 Object值的表示。

多載

名稱	Description
Concat(String, String, String, String)	串接四個指定的實例 String。
Concat(ReadOnlySpan<Char>, ReadOnlySpan<Char>, ReadOnlySpan<Char>, ReadOnlySpan<Char>)	串連四個指定唯讀字元範圍的字串表示。
Concat(String, String, String)	串接三個指定的實例 String。
Concat(ReadOnlySpan<Char>, ReadOnlySpan<Char>, ReadOnlySpan<Char>)	串連三個指定唯讀字元範圍的字串表示。
Concat(Object, Object, Object)	串連三個指定物件的字串表示。
Concat(String, String)	串接兩個指定的實例 String。
Concat(ReadOnlySpan<Object>)	串連指定之物件範圍中元素的字串表示。
Concat(Object, Object)	串連兩個指定物件的字串表示。
Concat(String[])	串接指定 String 陣列的元素。
Concat(ReadOnlySpan<String>)	串接指定張成 String的元素。
Concat(Object[])	串接指定陣列中 Object 元素的字串表示。
Concat(Object)	建立指定物件的字串表示。
Concat(IEnumerable<String>)	串接一個型態String為 的構造IEnumerable<T>集合的成員。
Concat(ReadOnlySpan<Char>, ReadOnlySpan<Char>)	串連兩個指定唯讀字元範圍的字串表示。
Concat<T>(IEnumerable<T>)	串接實作的 IEnumerable<T> 成員。

備註

注意

你也可以使用語言的字串串接運算子，例如 + C# 和 F#，或 & Visual Basic 中的 and + 來串接字串。 兩個編譯器都將連接運算子轉換成對 的 String.Concat其中一個超載的呼叫。

Concat(String, String, String, String)

來源:

String.Manipulation.cs

串接四個指定的實例 String。

public:
 static System::String ^ Concat(System::String ^ str0, System::String ^ str1, System::String ^ str2, System::String ^ str3);

public static string Concat(string? str0, string? str1, string? str2, string? str3);

static member Concat : string * string * string * string -> string

Public Shared Function Concat (str0 As String, str1 As String, str2 As String, str3 As String) As String

參數

str0

String

要串連的第一個字串。

str1

String

要串連的第二個字串。

str2

String

要串連的第三個字串。

str3

String

要串連的第四個字串。

傳回

String

、 和 的串接str0str2str1str3。

範例

下列範例會定義四個字母字組的陣列，並將其個別字母儲存至字串陣列，以便加以拼字。 接著它呼叫方法 Concat(String, String, String, String) 來重新組合被打亂的單字。

using System;
using System.Collections;

public class Example
{
   public static void Main()
   {
      const int WORD_SIZE = 4;
      
      // Define some 4-letter words to be scrambled.
      string[] words = { "home", "food", "game", "rest" };
      // Define two arrays equal to the number of letters in each word.
      double[] keys = new double[WORD_SIZE];
      string[] letters = new string[WORD_SIZE];
      // Initialize the random number generator.
      Random rnd = new Random();
      
      // Scramble each word.
      foreach (string word in words)
      {
         for (int ctr = 0; ctr < word.Length; ctr++)
         {
            // Populate the array of keys with random numbers.
            keys[ctr] = rnd.NextDouble();
            // Assign a letter to the array of letters.
            letters[ctr] = word[ctr].ToString();
         }   
         // Sort the array. 
         Array.Sort(keys, letters, 0, WORD_SIZE, Comparer.Default);      
         // Display the scrambled word.
         string scrambledWord = String.Concat(letters[0], letters[1], 
                                              letters[2], letters[3]);
         Console.WriteLine("{0} --> {1}", word, scrambledWord);
      } 
   }
}
// The example displays output like the following:
//       home --> mheo
//       food --> oodf
//       game --> aemg
//       rest --> trse

open System
open System.Collections

let WORD_SIZE = 4
      
// Define some 4-letter words to be scrambled.
let words = [| "home"; "food"; "game"; "rest" |]
// Define two arrays equal to the number of letters in each word.
let keys = Array.zeroCreate<float> WORD_SIZE
let letters = Array.zeroCreate<string> WORD_SIZE
// Initialize the random number generator.
let rnd = Random()

// Scramble each word.
for word in words do
    for i = 0 to word.Length - 1 do
        // Populate the array of keys with random numbers.
        keys[i] <- rnd.NextDouble()
        // Assign a letter to the array of letters.
        letters[i] <- string word[i]
    // Sort the array. 
    Array.Sort(keys, letters, 0, WORD_SIZE, Comparer.Default)      
    // Display the scrambled word.
    let scrambledWord = String.Concat(letters[0], letters[1], letters[2], letters[3])
    printfn $"{word} --> {scrambledWord}"
// The example displays output like the following:
//       home --> mheo
//       food --> oodf
//       game --> aemg
//       rest --> trse

Imports System.Collections

Module Example
   Public Sub Main()
      Const WORD_SIZE As Integer = 4
      
      ' Define some 4-letter words to be scrambled.
      Dim words() As String = { "home", "food", "game", "rest" }
      ' Define two arrays equal to the number of letters in each word.
      Dim keys(WORD_SIZE) As Double
      Dim letters(WORD_SIZE) As String
      ' Initialize the random number generator.
      Dim rnd As New Random()
      
      ' Scramble each word.
      For Each word As String In words
         For ctr As Integer = 0 To word.Length - 1
            ' Populate the array of keys with random numbers.
            keys(ctr) = rnd.NextDouble()
            ' Assign a letter to the array of letters.
            letters(ctr) = word.Chars(ctr)
         Next   
         ' Sort the array. 
         Array.Sort(keys, letters, 0, WORD_SIZE, Comparer.Default)      
         ' Display the scrambled word.
         Dim scrambledWord As String = String.Concat(letters(0), letters(1), _
                                                     letters(2), letters(3))
         Console.WriteLine("{0} --> {1}", word, scrambledWord)
      Next 
   End Sub
End Module 
' The example displays output like the following:
'       home --> mheo
'       food --> oodf
'       game --> aemg
'       rest --> trse

備註

此方法串 str0接 、 str1、 str2、 str3;且不添加任何分隔符。

另請參閱

• Join(String, String[])

Concat(ReadOnlySpan<Char>, ReadOnlySpan<Char>, ReadOnlySpan<Char>, ReadOnlySpan<Char>)

來源:

String.Manipulation.cs

串連四個指定唯讀字元範圍的字串表示。

public:
 static System::String ^ Concat(ReadOnlySpan<char> str0, ReadOnlySpan<char> str1, ReadOnlySpan<char> str2, ReadOnlySpan<char> str3);

public static string Concat(ReadOnlySpan<char> str0, ReadOnlySpan<char> str1, ReadOnlySpan<char> str2, ReadOnlySpan<char> str3);

static member Concat : ReadOnlySpan<char> * ReadOnlySpan<char> * ReadOnlySpan<char> * ReadOnlySpan<char> -> string

Public Shared Function Concat (str0 As ReadOnlySpan(Of Char), str1 As ReadOnlySpan(Of Char), str2 As ReadOnlySpan(Of Char), str3 As ReadOnlySpan(Of Char)) As String

參數

str0

ReadOnlySpan<Char>

要串連的第一個唯讀字元範圍。

str1

ReadOnlySpan<Char>

要串連的第二個唯讀字元範圍。

str2

ReadOnlySpan<Char>

要串連的第三個唯讀字元範圍。

str3

ReadOnlySpan<Char>

要串連的第四個唯讀字元範圍。

傳回

String

串接的串列表示，將 、 str1、 str2str3與 的值str0組成。

Concat(String, String, String)

來源:

String.Manipulation.cs

串接三個指定的實例 String。

public:
 static System::String ^ Concat(System::String ^ str0, System::String ^ str1, System::String ^ str2);

public static string Concat(string? str0, string? str1, string? str2);

static member Concat : string * string * string -> string

Public Shared Function Concat (str0 As String, str1 As String, str2 As String) As String

參數

str0

String

要串連的第一個字串。

str1

String

要串連的第二個字串。

str2

String

要串連的第三個字串。

傳回

String

、 、 和 str2的串接。str0str1

範例

以下範例使用此 Concat 方法將三串串接起來，並展示結果。

using System;

public class Example
{
   public static void Main()
   {
      String s1 = "We went to a bookstore, ";
      String s2 = "a movie, ";
      String s3 = "and a restaurant.";

      var s = String.Concat(s1, s2, s3);
      Console.WriteLine(s);
   }
}
// The example displays the following output:
//      We went to a bookstore, a movie, and a restaurant.

open System

let s1 = "We went to a bookstore, "
let s2 = "a movie, "
let s3 = "and a restaurant."

String.Concat(s1, s2, s3)
|> printfn "%s"
// The example displays the following output:
//      We went to a bookstore, a movie, and a restaurant.

Public Module Example
   Public Sub Main()
      Dim s1 As String = "We went to a bookstore, "
      Dim s2 As String = "a movie, "
      Dim s3 As String = "and a restaurant."

      Dim s = String.Concat(s1, s2, s3)
      Console.WriteLine(s)
   End Sub
End Module
' The example displays the following output:
'      We went to a bookstore, a movie, and a restaurant.

備註

此方法串 str0接 、 str1、 str2;且不添加任何分隔符。

另請參閱

• Join(String, String[])

Concat(ReadOnlySpan<Char>, ReadOnlySpan<Char>, ReadOnlySpan<Char>)

來源:

String.Manipulation.cs

串連三個指定唯讀字元範圍的字串表示。

public:
 static System::String ^ Concat(ReadOnlySpan<char> str0, ReadOnlySpan<char> str1, ReadOnlySpan<char> str2);

public static string Concat(ReadOnlySpan<char> str0, ReadOnlySpan<char> str1, ReadOnlySpan<char> str2);

static member Concat : ReadOnlySpan<char> * ReadOnlySpan<char> * ReadOnlySpan<char> -> string

Public Shared Function Concat (str0 As ReadOnlySpan(Of Char), str1 As ReadOnlySpan(Of Char), str2 As ReadOnlySpan(Of Char)) As String

參數

str0

ReadOnlySpan<Char>

要串連的第一個唯讀字元範圍。

str1

ReadOnlySpan<Char>

要串連的第二個唯讀字元範圍。

str2

ReadOnlySpan<Char>

要串連的第三個唯讀字元範圍。

傳回

String

這些是 、 和 str1str2的串str0接字串表示。

Concat(Object, Object, Object)

來源:

String.Manipulation.cs

串連三個指定物件的字串表示。

public:
 static System::String ^ Concat(System::Object ^ arg0, System::Object ^ arg1, System::Object ^ arg2);

public static string Concat(object? arg0, object? arg1, object? arg2);

static member Concat : obj * obj * obj -> string

Public Shared Function Concat (arg0 As Object, arg1 As Object, arg2 As Object) As String

參數

arg0

Object

要串連的第一個物件。

arg1

Object

要串連的第二個物件。

arg2

Object

要串連的第三個物件。

傳回

String

串接的串列表示，將 、 arg1、 arg2與 的值arg0組成。

範例

以下範例示範此 Concat 方法。

using System;

class stringConcat5 {
    public static void Main() {
    int i = -123;
    Object o = i;
    Object[] objs = new Object[] {-123, -456, -789};

    Console.WriteLine("Concatenate 1, 2, and 3 objects:");
    Console.WriteLine("1) {0}", String.Concat(o));
    Console.WriteLine("2) {0}", String.Concat(o, o));
    Console.WriteLine("3) {0}", String.Concat(o, o, o));

    Console.WriteLine("\nConcatenate 4 objects and a variable length parameter list:");
    Console.WriteLine("4) {0}", String.Concat(o, o, o, o));
    Console.WriteLine("5) {0}", String.Concat(o, o, o, o, o));

    Console.WriteLine("\nConcatenate a 3-element object array:");
    Console.WriteLine("6) {0}", String.Concat(objs));
    }
}
// The example displays the following output:
//    Concatenate 1, 2, and 3 objects:
//    1) -123
//    2) -123-123
//    3) -123-123-123
//
//    Concatenate 4 objects and a variable length parameter list:
//    4) -123-123-123-123
//    5) -123-123-123-123-123
//
//    Concatenate a 3-element object array:
//    6) -123-456-789

open System

let i = -123
let o: obj = i
let objs: obj[] = [| -123; -456; -789 |]

printfn "Concatenate 1, 2, and 3 objects:"
printfn $"1) {String.Concat o}"
printfn $"2) {String.Concat(o, o)}"
printfn $"3) {String.Concat(o, o, o)}"

printfn "\nConcatenate 4 objects and a variable length parameter list:"
printfn $"4) {String.Concat(o, o, o, o)}"
printfn $"5) {String.Concat(o, o, o, o, o)}"

printfn "\nConcatenate a 3-element object array:"
printfn $"6) {String.Concat objs}" 
// The example displays the following output:
//    Concatenate 1, 2, and 3 objects:
//    1) -123
//    2) -123-123
//    3) -123-123-123
//
//    Concatenate 4 objects and a variable length parameter list:
//    4) -123-123-123-123
//    5) -123-123-123-123-123
//
//    Concatenate a 3-element object array:
//    6) -123-456-789

Class stringConcat5
   Public Shared Sub Main()
      Dim i As Integer = - 123
      Dim o As [Object] = i
      Dim objs() As [Object] = {-123, -456, -789}
      
      Console.WriteLine("Concatenate 1, 2, and 3 objects:")
      Console.WriteLine("1) {0}", [String].Concat(o))
      Console.WriteLine("2) {0}", [String].Concat(o, o))
      Console.WriteLine("3) {0}", [String].Concat(o, o, o))
      
      Console.WriteLine(vbCrLf & "Concatenate 4 objects and a variable length parameter list:")
      Console.WriteLine("4) {0}", String.Concat(o, o, o, o))
      Console.WriteLine("5) {0}", String.Concat(o, o, o, o, o))
      
      Console.WriteLine(vbCrLf & "Concatenate a 3-element object array:")
      Console.WriteLine("6) {0}", [String].Concat(objs))
   End Sub
End Class
'The example displays the following output:
'    Concatenate 1, 2, and 3 objects:
'    1) -123
'    2) -123-123
'    3) -123-123-123
'    
'    Concatenate 4 objects and a variable length parameter list:
'    4) -123-123-123-123
'    5) -123-123-123-123-123
'         
'    Concatenate a 3-element object array:
'    6) -123-456-789

備註

該方法串 arg0接 、 arg1，並 arg2 呼叫每個物件的無 ToString 參數方法;它不添加任何分隔符。

String.Empty 用來取代任何空參數。

另請參閱

• Object
• Join(String, String[])

Concat(String, String)

來源:

String.Manipulation.cs

串接兩個指定的實例 String。

public:
 static System::String ^ Concat(System::String ^ str0, System::String ^ str1);

public static string Concat(string? str0, string? str1);

static member Concat : string * string -> string

Public Shared Function Concat (str0 As String, str1 As String) As String

參數

str0

String

要串連的第一個字串。

str1

String

要串連的第二個字串。

傳回

String

與 str1的串接str0。

範例

下列範例會串連人員的第一個、中間和姓氏。

using System;

public class ConcatTest {
    public static void Main() {

        // we want to simply quickly add this person's name together
        string fName = "Simon";
        string mName = "Jake";
        string lName = "Harrows";

        // because we want a name to appear with a space in between each name,
        // put a space on the front of the middle, and last name, allowing for
        // the fact that a space may already be there
        mName = " " + mName.Trim();
        lName = " " + lName.Trim();

        // this line simply concatenates the two strings
        Console.WriteLine("Welcome to this page, '{0}'!", string.Concat( string.Concat(fName, mName), lName ) );
    }
}
// The example displays the following output:
//        Welcome to this page, 'Simon Jake Harrows'!

open System

[<EntryPoint>]
let main _ =
    // we want to simply quickly add this person's name together
    let fName = "Simon"
    let mName = "Jake"
    let lName = "Harrows"

    // because we want a name to appear with a space in between each name,
    // put a space on the front of the middle, and last name, allowing for
    // the fact that a space may already be there
    let mName = " " + mName.Trim()
    let lName = " " + lName.Trim()

    // this line simply concatenates the two strings
    printfn $"Welcome to this page, '{String.Concat(String.Concat(fName, mName), lName)}'!"
    0
// The example displays the following output:
//        Welcome to this page, 'Simon Jake Harrows'!

Public Class ConcatTest
    Public Shared Sub Main()
        Dim fName As String = "Simon"
        Dim mName As String = "Jake"
        Dim lName As String = "Harrows"
        
        ' We want to simply quickly add this person's name together.
        ' Because we want a name to appear with a space in between each name, 
        ' we put a space on the front of the middle, and last name, allowing for
        ' the fact that a space may already be there.
        mName = " " + mName.Trim()
        lName = " " + lName.Trim()
        
        ' This line simply concatenates the two strings.
        Console.WriteLine("Welcome to this page, '{0}'!", _
                          String.Concat(String.Concat(fName, mName), lName))
    End Sub
End Class
' The example displays the following output:
'       Welcome to this page, 'Simon Jake Harrows'!

備註

此方法串 str0 接 與 str1;不添加任何分隔符。

Empty字串會用來取代任何空參數。

另請參閱

• Join(String, String[])

Concat(ReadOnlySpan<Object>)

來源:

String.Manipulation.cs

串連指定之物件範圍中元素的字串表示。

public:
 static System::String ^ Concat(ReadOnlySpan<System::Object ^> args);

public static string Concat(scoped ReadOnlySpan<object?> args);

static member Concat : ReadOnlySpan<obj> -> string

Public Shared Function Concat (args As ReadOnlySpan(Of Object)) As String

參數

args

ReadOnlySpan<Object>

物件範圍，其中包含要串連的專案。

傳回

String

元素值 args的串接字串表示。

Concat(Object, Object)

來源:

String.Manipulation.cs

串連兩個指定物件的字串表示。

public:
 static System::String ^ Concat(System::Object ^ arg0, System::Object ^ arg1);

public static string Concat(object? arg0, object? arg1);

static member Concat : obj * obj -> string

Public Shared Function Concat (arg0 As Object, arg1 As Object) As String

參數

arg0

Object

要串連的第一個物件。

arg1

Object

要串連的第二個物件。

傳回

String

與 的串arg0arg1接字串表示。

範例

以下範例示範此 Concat 方法。

using System;

class stringConcat5 {
    public static void Main() {
    int i = -123;
    Object o = i;
    Object[] objs = new Object[] {-123, -456, -789};

    Console.WriteLine("Concatenate 1, 2, and 3 objects:");
    Console.WriteLine("1) {0}", String.Concat(o));
    Console.WriteLine("2) {0}", String.Concat(o, o));
    Console.WriteLine("3) {0}", String.Concat(o, o, o));

    Console.WriteLine("\nConcatenate 4 objects and a variable length parameter list:");
    Console.WriteLine("4) {0}", String.Concat(o, o, o, o));
    Console.WriteLine("5) {0}", String.Concat(o, o, o, o, o));

    Console.WriteLine("\nConcatenate a 3-element object array:");
    Console.WriteLine("6) {0}", String.Concat(objs));
    }
}
// The example displays the following output:
//    Concatenate 1, 2, and 3 objects:
//    1) -123
//    2) -123-123
//    3) -123-123-123
//
//    Concatenate 4 objects and a variable length parameter list:
//    4) -123-123-123-123
//    5) -123-123-123-123-123
//
//    Concatenate a 3-element object array:
//    6) -123-456-789

open System

let i = -123
let o: obj = i
let objs: obj[] = [| -123; -456; -789 |]

printfn "Concatenate 1, 2, and 3 objects:"
printfn $"1) {String.Concat o}"
printfn $"2) {String.Concat(o, o)}"
printfn $"3) {String.Concat(o, o, o)}"

printfn "\nConcatenate 4 objects and a variable length parameter list:"
printfn $"4) {String.Concat(o, o, o, o)}"
printfn $"5) {String.Concat(o, o, o, o, o)}"

printfn "\nConcatenate a 3-element object array:"
printfn $"6) {String.Concat objs}" 
// The example displays the following output:
//    Concatenate 1, 2, and 3 objects:
//    1) -123
//    2) -123-123
//    3) -123-123-123
//
//    Concatenate 4 objects and a variable length parameter list:
//    4) -123-123-123-123
//    5) -123-123-123-123-123
//
//    Concatenate a 3-element object array:
//    6) -123-456-789

Class stringConcat5
   Public Shared Sub Main()
      Dim i As Integer = - 123
      Dim o As [Object] = i
      Dim objs() As [Object] = {-123, -456, -789}
      
      Console.WriteLine("Concatenate 1, 2, and 3 objects:")
      Console.WriteLine("1) {0}", [String].Concat(o))
      Console.WriteLine("2) {0}", [String].Concat(o, o))
      Console.WriteLine("3) {0}", [String].Concat(o, o, o))
      
      Console.WriteLine(vbCrLf & "Concatenate 4 objects and a variable length parameter list:")
      Console.WriteLine("4) {0}", String.Concat(o, o, o, o))
      Console.WriteLine("5) {0}", String.Concat(o, o, o, o, o))
      
      Console.WriteLine(vbCrLf & "Concatenate a 3-element object array:")
      Console.WriteLine("6) {0}", [String].Concat(objs))
   End Sub
End Class
'The example displays the following output:
'    Concatenate 1, 2, and 3 objects:
'    1) -123
'    2) -123-123
'    3) -123-123-123
'    
'    Concatenate 4 objects and a variable length parameter list:
'    4) -123-123-123-123
'    5) -123-123-123-123-123
'         
'    Concatenate a 3-element object array:
'    6) -123-456-789

備註

該方法透過arg0arg1呼叫無ToString參數方法arg0arg1與 ，將 和 串接;它不會加入任何分隔符。

String.Empty 用來取代任何空參數。

如果其中一個自變數是數位參考，則方法會串連代表該陣列的字串，而不是其成員（例如“System.String[]”。

另請參閱

• Object
• Join(String, String[])

Concat(String[])

來源:

String.Manipulation.cs

重要

此 API 不符合 CLS 規範。

串接指定 String 陣列的元素。

public:
 static System::String ^ Concat(... cli::array <System::String ^> ^ values);

public static string Concat(params string?[] values);

static member Concat : string[] -> string

Public Shared Function Concat (ParamArray values As String()) As String

參數

values

String[]

字串實例的陣列。

傳回

String

的 values串接元素。

例外狀況

ArgumentNullException

values 為 null。

OutOfMemoryException

記憶體不足。

範例

以下範例示範了該方法與陣String列的使用Concat。

using System;

public class Example
{
    public static void Main()
    {
        // Make an array of strings. Note that we have included spaces.
        string [] s = { "hello ", "and ", "welcome ", "to ",
                        "this ", "demo! " };

        // Put all the strings together.
        Console.WriteLine(string.Concat(s));

        // Sort the strings, and put them together.
        Array.Sort(s);
        Console.WriteLine(string.Concat(s));
    }
}
// The example displays the following output:
//       hello and welcome to this demo!
//       and demo! hello this to welcome

open System

// Make an array of strings. Note that we have included spaces.
let s = 
    [| "hello "; "and "; "welcome "; "to "
       "this "; "demo! " |]

// Put all the strings together.
printfn $"{String.Concat s}"

// Sort the strings, and put them together.
Array.Sort s
printfn $"{String.Concat s}"
// The example displays the following output:
//       hello and welcome to this demo!
//       and demo! hello this to welcome

Public Class Example
    Public Shared Sub Main()
        ' Make an array of strings. Note that we have included spaces.
        Dim s As String() = { "hello ", "and ", "welcome ", "to ",
                              "this ", "demo! "}

        ' Put all the strings together.
        Console.WriteLine(String.Concat(s))
        
        ' Sort the strings, and put them together.
        Array.Sort(s)
        Console.WriteLine(String.Concat(s))
    End Sub
End Class
' The example displays the following output:
'       hello and welcome to this demo!
'       and demo! hello this to welcome

備註

此方法將每個物件串接; values它不添加任何分隔符。

Empty字串會用來取代陣列中任何空物件。

另請參閱

• Join(String, String[])

Concat(ReadOnlySpan<String>)

來源:

String.Manipulation.cs

串接指定張成 String的元素。

public:
 static System::String ^ Concat(ReadOnlySpan<System::String ^> values);

public static string Concat(scoped ReadOnlySpan<string?> values);

static member Concat : ReadOnlySpan<string> -> string

Public Shared Function Concat (values As ReadOnlySpan(Of String)) As String

參數

values

ReadOnlySpan<String>

跨越一連串 String 的實例。

傳回

String

的 values串接元素。

Concat(Object[])

來源:

String.Manipulation.cs

串接指定陣列中 Object 元素的字串表示。

public:
 static System::String ^ Concat(... cli::array <System::Object ^> ^ args);

public static string Concat(params object?[] args);

static member Concat : obj[] -> string

Public Shared Function Concat (ParamArray args As Object()) As String

參數

args

Object[]

對象陣列，其中包含要串連的專案。

傳回

String

元素值 args的串接字串表示。

例外狀況

ArgumentNullException

args 為 null。

OutOfMemoryException

記憶體不足。

範例

以下範例展示了該方法與陣列的Object應用Concat。

using System;

public class ConcatTest {
    public static void Main() {
        // Create a group of objects.
        Test1 t1 = new Test1();
        Test2 t2 = new Test2();
        int i = 16;
        string s = "Demonstration";

        // Place the objects in an array.
        object [] o = { t1, i, t2, s };

        // Concatenate the objects together as a string. To do this,
        // the ToString method of each of the objects is called.
        Console.WriteLine(string.Concat(o));
    }
}

// Create two empty test classes.
class Test1 {
}

class Test2 {
}
// The example displays the following output:
//       Test116Test2Demonstration

open System

// Create two empty test classes.
type Test1() = class end

type Test2() = class end

// Create a group of objects.
let t1 = new Test1()
let t2 = new Test2()
let i = 16
let s = "Demonstration"

// Place the objects in an array.
let o: obj[] = [| t1; i; t2; s |]

// Concatenate the objects together as a string. To do this,
// the ToString method of each of the objects is called.
printfn $"{String.Concat o}"

// The example displays the following output:
//       Test116Test2Demonstration

Public Class ConcatTest
    
    Public Shared Sub Main()
        Dim t1 As New Test1()
        Dim t2 As New Test2()
        Dim i As Integer = 16
        Dim s As String = "Demonstration"
        Dim o As Object() = {t1, i, t2, s}
        
        ' create a group of objects
        
        ' place the objects in an array
        
        ' concatenate the objects together as a string. To do this,
        ' the ToString method in the objects is called
        Console.WriteLine(String.Concat(o))
    End Sub
End Class


' imagine these test classes are full-fledged objects...
Class Test1
End Class

Class Test2
End Class

備註

該方法透過呼叫該物件的無ToString參數方法來串接每個物件;args它不添加任何分隔符。

String.Empty 用來取代陣列中任一個空物件。

給呼叫者的注意事項

C++程式代碼不會呼叫這個方法。 C++ 編譯器會將具有四個或以上物件參數的呼叫 Concat 解析為 Concat(Object, Object, Object, Object)。

另請參閱

• Object
• Join(String, String[])

Concat(Object)

來源:

String.Manipulation.cs

建立指定物件的字串表示。

public:
 static System::String ^ Concat(System::Object ^ arg0);

public static string Concat(object? arg0);

static member Concat : obj -> string

Public Shared Function Concat (arg0 As Object) As String

參數

arg0

Object

要表示的對象，或 null。

傳回

String

若 為 null，則 的字arg0arg0Empty串表示。

範例

以下範例示範此 Concat 方法。

using System;

class stringConcat5 {
    public static void Main() {
    int i = -123;
    Object o = i;
    Object[] objs = new Object[] {-123, -456, -789};

    Console.WriteLine("Concatenate 1, 2, and 3 objects:");
    Console.WriteLine("1) {0}", String.Concat(o));
    Console.WriteLine("2) {0}", String.Concat(o, o));
    Console.WriteLine("3) {0}", String.Concat(o, o, o));

    Console.WriteLine("\nConcatenate 4 objects and a variable length parameter list:");
    Console.WriteLine("4) {0}", String.Concat(o, o, o, o));
    Console.WriteLine("5) {0}", String.Concat(o, o, o, o, o));

    Console.WriteLine("\nConcatenate a 3-element object array:");
    Console.WriteLine("6) {0}", String.Concat(objs));
    }
}
// The example displays the following output:
//    Concatenate 1, 2, and 3 objects:
//    1) -123
//    2) -123-123
//    3) -123-123-123
//
//    Concatenate 4 objects and a variable length parameter list:
//    4) -123-123-123-123
//    5) -123-123-123-123-123
//
//    Concatenate a 3-element object array:
//    6) -123-456-789

open System

let i = -123
let o: obj = i
let objs: obj[] = [| -123; -456; -789 |]

printfn "Concatenate 1, 2, and 3 objects:"
printfn $"1) {String.Concat o}"
printfn $"2) {String.Concat(o, o)}"
printfn $"3) {String.Concat(o, o, o)}"

printfn "\nConcatenate 4 objects and a variable length parameter list:"
printfn $"4) {String.Concat(o, o, o, o)}"
printfn $"5) {String.Concat(o, o, o, o, o)}"

printfn "\nConcatenate a 3-element object array:"
printfn $"6) {String.Concat objs}" 
// The example displays the following output:
//    Concatenate 1, 2, and 3 objects:
//    1) -123
//    2) -123-123
//    3) -123-123-123
//
//    Concatenate 4 objects and a variable length parameter list:
//    4) -123-123-123-123
//    5) -123-123-123-123-123
//
//    Concatenate a 3-element object array:
//    6) -123-456-789

Class stringConcat5
   Public Shared Sub Main()
      Dim i As Integer = - 123
      Dim o As [Object] = i
      Dim objs() As [Object] = {-123, -456, -789}
      
      Console.WriteLine("Concatenate 1, 2, and 3 objects:")
      Console.WriteLine("1) {0}", [String].Concat(o))
      Console.WriteLine("2) {0}", [String].Concat(o, o))
      Console.WriteLine("3) {0}", [String].Concat(o, o, o))
      
      Console.WriteLine(vbCrLf & "Concatenate 4 objects and a variable length parameter list:")
      Console.WriteLine("4) {0}", String.Concat(o, o, o, o))
      Console.WriteLine("5) {0}", String.Concat(o, o, o, o, o))
      
      Console.WriteLine(vbCrLf & "Concatenate a 3-element object array:")
      Console.WriteLine("6) {0}", [String].Concat(objs))
   End Sub
End Class
'The example displays the following output:
'    Concatenate 1, 2, and 3 objects:
'    1) -123
'    2) -123-123
'    3) -123-123-123
'    
'    Concatenate 4 objects and a variable length parameter list:
'    4) -123-123-123-123
'    5) -123-123-123-123-123
'         
'    Concatenate a 3-element object array:
'    6) -123-456-789

備註

該Concat(Object)方法透過呼叫其無ToString參數方法表示arg0為字串。

另請參閱

• Object
• Join(String, String[])

Concat(IEnumerable<String>)

來源:

String.Manipulation.cs

串接一個型態String為 的構造IEnumerable<T>集合的成員。

public:
 static System::String ^ Concat(System::Collections::Generic::IEnumerable<System::String ^> ^ values);

public static string Concat(System.Collections.Generic.IEnumerable<string?> values);

static member Concat : seq<string> -> string

Public Shared Function Concat (values As IEnumerable(Of String)) As String

參數

values

IEnumerable<String>

一個實 IEnumerable<T> 作 且其泛型參數為 String的集合物件。

傳回

String

串接的 values字串 ，或 Empty 若 values 為空 IEnumerable(Of String)。

例外狀況

ArgumentNullException

values 為 null。

範例

下列範例會使用 Eratosthenes 演算法的 Sieve 來計算小於或等於 100 的質數。 它將結果指派給List<T>一個型別String為 的物件，然後將該物件傳給方法。Concat(IEnumerable<String>)

using System;
using System.Collections.Generic;

public class Example
{
   public static void Main()
   {
      int maxPrime = 100;
      IEnumerable<String> primeList = GetPrimes(maxPrime);
      Console.WriteLine("Primes less than {0}:", maxPrime);
      Console.WriteLine("   {0}", String.Concat(primeList));
   }

   private static IEnumerable<String> GetPrimes(int maxPrime)
   {
      Array values = Array.CreateInstance(typeof(int), 
                              new int[] { maxPrime - 1}, new int[] { 2 }); 
      // Use Sieve of Erathsthenes to determine prime numbers.
      for (int ctr = values.GetLowerBound(0); ctr <= (int) Math.Ceiling(Math.Sqrt(values.GetUpperBound(0))); ctr++)
      {
                           
         if ((int) values.GetValue(ctr) == 1) continue;
         
         for (int multiplier = ctr; multiplier <=  maxPrime / 2; multiplier++)
            if (ctr * multiplier <= maxPrime)
               values.SetValue(1, ctr * multiplier);
      }      
      
      List<String> primes = new List<String>();
      for (int ctr = values.GetLowerBound(0); ctr <= values.GetUpperBound(0); ctr++)
         if ((int) values.GetValue(ctr) == 0) 
            primes.Add(ctr.ToString() + " ");
      return primes;
   }   
}
// The example displays the following output:
//    Primes less than 100:
//       2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97

open System

let getPrimes maxPrime =
    let values = Array.CreateInstance(typeof<int>, [| maxPrime - 1|], [| 2 |]) 
    // Use Sieve of Erathsthenes to determine prime numbers.
    for i = values.GetLowerBound 0 to values.GetUpperBound 0 |> float |> sqrt |> ceil |> int do
        if values.GetValue i :?> int <> 1 then
            for multiplier = i to maxPrime / 2 do
                if i * multiplier <= maxPrime then
                    values.SetValue(1, i * multiplier)
    seq {
        for i = values.GetLowerBound 0 to values.GetUpperBound 0 do
            if values.GetValue i :?> int = 0 then
                string i + " "
    }    

let maxPrime = 100
let primeList = getPrimes maxPrime
printfn $"Primes less than {maxPrime}:"
printfn $"   {String.Concat primeList}"

// The example displays the following output:
//    Primes less than 100:
//       2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97

Imports System.Collections.Generic

Module Example
   Public Sub Main()
      Dim maxPrime As Integer = 100
      Dim primeList As IEnumerable(Of String) = GetPrimes(maxPrime)
      Console.WriteLine("Primes less than {0}:", maxPrime)
      Console.WriteLine("   {0}", String.Concat(primeList))
   End Sub
   
   Private Function GetPrimes(maxPrime As Integer) As IEnumerable(Of String)
      Dim values As Array = Array.CreateInstance(GetType(Integer), _
                              New Integer() { maxPrime - 1}, New Integer(){ 2 }) 
      ' Use Sieve of Erathsthenes to determine prime numbers.
      For ctr As Integer = values.GetLowerBound(0) To _
                           CInt(Math.Ceiling(Math.Sqrt(values.GetUpperBound(0))))
         If CInt(values.GetValue(ctr)) = 1 Then Continue For
         
         For multiplier As Integer = ctr To maxPrime \ 2
            If ctr * multiplier <= maxPrime Then values.SetValue(1, ctr * multiplier)
         Next   
      Next      
      
      Dim primes As New List(Of String)
      For ctr As Integer = values.GetLowerBound(0) To values.GetUpperBound(0)
         If CInt(values.GetValue(ctr)) = 0 Then primes.Add(ctr.ToString() + " ")
      Next            
      Return primes
   End Function   
End Module
' The example displays the following output:
'    Primes less than 100:
'       2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97

備註

此方法將每個物件串接; values它不添加任何分隔符。 若要在 的 values每個成員之間指定分隔符，請呼叫 該 Join(String, IEnumerable<String>) 方法。

Empty字串可替代中values任意零元素。

若 values 為空 IEnumerable(Of String)，則方法返回 String.Empty。 若 values ， null則方法拋 ArgumentNullException 出例外。

Concat(IEnumerable<String>) 這是一種方便的方法，讓你可以將集合中的 IEnumerable(Of String) 每個元素串接起來，而不必先將元素轉換成字串陣列。 它特別適合用於 Language-Integrated 查詢（LINQ）查詢表達式。 以下範例將包含 List(Of String) 字母表大寫或小寫字母的物件傳遞給一個 lambda 運算式，該表達式選擇等於或大於某個特定字母的字母（在本例中為「M」）。 IEnumerable(Of String)方法回傳Enumerable.Where的集合會傳給方法，Concat(IEnumerable<String>)以單一字串顯示結果。

using System;
using System.Collections.Generic;
using System.Linq;

public class Example
{
   public static void Main()
   {
      string output = String.Concat( GetAlphabet(true).Where( letter => 
                      letter.CompareTo("M") >= 0));
      Console.WriteLine(output);  
   }

   private static List<string> GetAlphabet(bool upper)
   {
      List<string> alphabet = new List<string>();
      int charValue = upper ? 65 : 97;
      for (int ctr = 0; ctr <= 25; ctr++)
         alphabet.Add(((char)(charValue + ctr)).ToString());
      return alphabet; 
   }
}
// The example displays the following output:
//      MNOPQRSTUVWXYZ

// This example uses the F# Seq.filter function instead of Linq.
open System

let getAlphabet upper =
    let charValue = if upper then 65 else 97
    seq {
        for i = 0 to 25 do
            charValue + i |> char |> string
    }

getAlphabet true
|> Seq.filter (fun letter -> letter.CompareTo "M" >= 0)
|> String.Concat
|> printfn "%s"
// The example displays the following output:
//      MNOPQRSTUVWXYZ

Imports System.Collections.Generic
Imports System.Linq

Module modMain
   Public Sub Main()
      Dim output As String = String.Concat(GetAlphabet(true).Where(Function(letter) _
                                                         letter >= "M"))
        
      Console.WriteLine(output)                                     
   End Sub
   
   Private Function GetAlphabet(upper As Boolean) As List(Of String)
      Dim alphabet As New List(Of String)
      Dim charValue As Integer = CInt(IIf(upper, 65, 97))
      For ctr As Integer = 0 To 25
         alphabet.Add(ChrW(charValue + ctr).ToString())
      Next
      Return alphabet 
   End Function
End Module
' The example displays the following output:
'       MNOPQRSTUVWXYZ

Concat(ReadOnlySpan<Char>, ReadOnlySpan<Char>)

來源:

String.Manipulation.cs

串連兩個指定唯讀字元範圍的字串表示。

public:
 static System::String ^ Concat(ReadOnlySpan<char> str0, ReadOnlySpan<char> str1);

public static string Concat(ReadOnlySpan<char> str0, ReadOnlySpan<char> str1);

static member Concat : ReadOnlySpan<char> * ReadOnlySpan<char> -> string

Public Shared Function Concat (str0 As ReadOnlySpan(Of Char), str1 As ReadOnlySpan(Of Char)) As String

參數

str0

ReadOnlySpan<Char>

要串連的第一個唯讀字元範圍。

str1

ReadOnlySpan<Char>

要串連的第二個唯讀字元範圍。

傳回

String

與 的串str0str1接字串表示。

Concat<T>(IEnumerable<T>)

來源:

String.Manipulation.cs

串接實作的 IEnumerable<T> 成員。

public:
generic <typename T>
 static System::String ^ Concat(System::Collections::Generic::IEnumerable<T> ^ values);

public static string Concat<T>(System.Collections.Generic.IEnumerable<T> values);

static member Concat : seq<'T> -> string

Public Shared Function Concat(Of T) (values As IEnumerable(Of T)) As String

類型參數

T

成員類型 values。

參數

values

IEnumerable<T>

一個實 IEnumerable<T> 作介面的集合物件。

傳回

String

中所串接的成員 values。

例外狀況

ArgumentNullException

values 為 null。

範例

以下範例定義了一個非常簡單的 Animal 類別，包含動物名稱及其所屬的目。 接著它定義一個 List<T> 物件包含若干物件 Animal 。 Enumerable.Where呼叫擴展方法來擷取Animal屬性Order等於「Rodent」的物件。 結果會傳入 Concat<T>(IEnumerable<T>) 方法並顯示到主控台。

using System;
using System.Collections.Generic;
using System.Linq;

public class Animal
{
   public string Kind;
   public string Order;
   
   public Animal(string kind, string order)
   {
      this.Kind = kind;
      this.Order = order;
   }
   
   public override string ToString()
   {
      return this.Kind;
   }
}

public class Example
{
   public static void Main()
   {
      List<Animal> animals = new List<Animal>();
      animals.Add(new Animal("Squirrel", "Rodent"));
      animals.Add(new Animal("Gray Wolf", "Carnivora"));
      animals.Add(new Animal("Capybara", "Rodent"));
      string output = String.Concat(animals.Where( animal => 
                      (animal.Order == "Rodent")));
      Console.WriteLine(output);  
   }
}
// The example displays the following output:
//      SquirrelCapybara

// This example uses the F# Seq.filter function instead of Linq.
open System

type Animal =
  { Kind: string
    Order: string }
    override this.ToString() =
       this.Kind

let animals = ResizeArray()
animals.Add { Kind = "Squirrel"; Order = "Rodent" }
animals.Add { Kind = "Gray Wolf"; Order = "Carnivora" }
animals.Add { Kind = "Capybara"; Order = "Rodent" }

Seq.filter (fun animal -> animal.Order = "Rodent")
|> String.Concat
|> printfn "%s"
// The example displays the following output:
//      SquirrelCapybara

Imports System.Collections.Generic

Public Class Animal
   Public Kind As String
   Public Order As String
   
   Public Sub New(kind As String, order As String)
      Me.Kind = kind
      Me.Order = order
   End Sub
   
   Public Overrides Function ToString() As String
      Return Me.Kind
   End Function
End Class

Module Example
   Public Sub Main()
      Dim animals As New List(Of Animal)
      animals.Add(New Animal("Squirrel", "Rodent"))
      animals.Add(New Animal("Gray Wolf", "Carnivora"))
      animals.Add(New Animal("Capybara", "Rodent")) 
      Dim output As String = String.Concat(animals.Where(Function(animal) _
                                           animal.Order = "Rodent"))
      Console.WriteLine(output)                                           
   End Sub
End Module
' The example displays the following output:
'      SquirrelCapybara

備註

此方法將每個物件串接; values它不添加任何分隔符。

Empty字串會用來取代任何空參數。

Concat<T>(IEnumerable<T>) 這是一種方便的方法，讓你能在不先將元素轉換成字串的情況下，將集合中的 IEnumerable<T> 每個元素串接起來。 如範例所示，它特別適用於 Language-Integrated 查詢（LINQ）查詢表達式。 集合中 IEnumerable<T> 每個物件的字串表示是透過呼叫該物件的方法 ToString 推導出來的。