String.Join String.Join String.Join String.Join Method

定義

指定した配列の要素またはコレクションのメンバーを連結します。各要素の間には、指定した区切り記号が挿入されます。Concatenates the elements of a specified array or the members of a collection, using the specified separator between each element or member.

オーバーロード

Join(String, String[], Int32, Int32) Join(String, String[], Int32, Int32) Join(String, String[], Int32, Int32) Join(String, String[], Int32, Int32)

文字列配列の指定した要素を連結します。各要素の間には、指定した区切り記号が挿入されます。Concatenates the specified elements of a string array, using the specified separator between each element.

Join(Char, String[], Int32, Int32) Join(Char, String[], Int32, Int32) Join(Char, String[], Int32, Int32) Join(Char, String[], Int32, Int32)
Join(String, String[]) Join(String, String[]) Join(String, String[]) Join(String, String[])

文字列配列のすべての要素を連結します。各要素の間には、指定した区切り記号が挿入されます。Concatenates all the elements of a string array, using the specified separator between each element.

Join(Char, Object[]) Join(Char, Object[]) Join(Char, Object[]) Join(Char, Object[])
Join(String, IEnumerable<String>) Join(String, IEnumerable<String>) Join(String, IEnumerable<String>) Join(String, IEnumerable<String>)

IEnumerable<T> 型の構築された String コレクションのメンバーを連結します。各メンバーの間には、指定した区切り記号が挿入されます。Concatenates the members of a constructed IEnumerable<T> collection of type String, using the specified separator between each member.

Join(String, Object[]) Join(String, Object[]) Join(String, Object[]) Join(String, Object[])

オブジェクト配列の要素を連結します。各要素の間には、指定した区切り記号が挿入されます。Concatenates the elements of an object array, using the specified separator between each element.

Join(Char, String[]) Join(Char, String[]) Join(Char, String[]) Join(Char, String[])
Join<T>(Char, IEnumerable<T>) Join<T>(Char, IEnumerable<T>) Join<T>(Char, IEnumerable<T>) Join<T>(Char, IEnumerable<T>)
Join<T>(String, IEnumerable<T>) Join<T>(String, IEnumerable<T>) Join<T>(String, IEnumerable<T>) Join<T>(String, IEnumerable<T>)

コレクションのメンバーを連結します。各メンバーの間には、指定した区切り記号が挿入されます。Concatenates the members of a collection, using the specified separator between each member.

Join(String, String[], Int32, Int32) Join(String, String[], Int32, Int32) Join(String, String[], Int32, Int32) Join(String, String[], Int32, Int32)

文字列配列の指定した要素を連結します。各要素の間には、指定した区切り記号が挿入されます。Concatenates the specified elements of a string array, using the specified separator between each element.

public:
 static System::String ^ Join(System::String ^ separator, cli::array <System::String ^> ^ value, int startIndex, int count);
public static string Join (string separator, string[] value, int startIndex, int count);
static member Join : string * string[] * int * int -> string
Public Shared Function Join (separator As String, value As String(), startIndex As Integer, count As Integer) As String

パラメーター

separator
String String String String

区切り記号として使用する文字列。The string to use as a separator. value が 2 つ以上の要素を含む場合のみ、separator が返される文字列に含まれます。separator is included in the returned string only if value has more than one element.

value
String[]

連結する要素を格納している配列。An array that contains the elements to concatenate.

startIndex
Int32 Int32 Int32 Int32

使用する value の最初の要素。The first element in value to use.

count
Int32 Int32 Int32 Int32

使用する value の要素の数。The number of elements of value to use.

戻り値

value 内の文字列からなる、separator 文字列で区切られた文字列。A string that consists of the strings in value delimited by the separator string.

または-or- Empty が 0 である場合、または count に要素がない場合、または valueseparator のすべての要素が value である場合、EmptyEmpty if count is zero, value has no elements, or separator and all the elements of value are Empty.

例外

startIndex または count が 0 未満です。startIndex or count is less than 0.

または-or- startIndexcount を加算すると、value にある要素の数を超えます。startIndex plus count is greater than the number of elements in value.

メモリが不足しています。Out of memory.

次の例では、果物の名前の配列から 2 つの要素を連結します。The following example concatenates two elements from an array of names of fruit.

// Sample for String::Join(String, String[], int int)
using namespace System;
int main()
{
   array<String^>^val = {"apple","orange","grape","pear"};
   String^ sep = ", ";
   String^ result;
   Console::WriteLine( "sep = '{0}'", sep );
   Console::WriteLine( "val[] = {{'{0}' '{1}' '{2}' '{3}'}}", val[ 0 ], val[ 1 ], val[ 2 ], val[ 3 ] );
   result = String::Join( sep, val, 1, 2 );
   Console::WriteLine( "String::Join(sep, val, 1, 2) = '{0}'", result );
}

/*
This example produces the following results:
sep = ', '
val[] = {'apple' 'orange' 'grape' 'pear'}
String::Join(sep, val, 1, 2) = 'orange, grape'
*/
// Sample for String.Join(String, String[], int int)
using System;

class Sample {
    public static void Main() {
    String[] val = {"apple", "orange", "grape", "pear"};
    String sep   = ", ";
    String result;

    Console.WriteLine("sep = '{0}'", sep);
    Console.WriteLine("val[] = {{'{0}' '{1}' '{2}' '{3}'}}", val[0], val[1], val[2], val[3]);
    result = String.Join(sep, val, 1, 2);
    Console.WriteLine("String.Join(sep, val, 1, 2) = '{0}'", result);
    }
}
/*
This example produces the following results:
sep = ', '
val[] = {'apple' 'orange' 'grape' 'pear'}
String.Join(sep, val, 1, 2) = 'orange, grape'
*/
Class Sample
   Public Shared Sub Main()
      Dim val As [String]() =  {"apple", "orange", "grape", "pear"}
      Dim sep As [String] = ", "
      Dim result As [String]
      
      Console.WriteLine("sep = '{0}'", sep)
      Console.WriteLine("val() = {{'{0}' '{1}' '{2}' '{3}'}}", val(0), val(1), val(2), val(3))
      result = [String].Join(sep, val, 1, 2)
      Console.WriteLine("String.Join(sep, val, 1, 2) = '{0}'", result)
   End Sub
End Class 
'This example displays the following output:
'       sep = ', '
'       val() = {'apple' 'orange' 'grape' 'pear'}
'       String.Join(sep, val, 1, 2) = 'orange, grape'

注釈

たとえば場合、separatorは「,」の要素がvalueは、"apple"、「オレンジ」、"grape"および"pear"Join(separator, value, 1, 2)を返します「オレンジ、grape」。For example, if separator is ", " and the elements of value are "apple", "orange", "grape", and "pear", Join(separator, value, 1, 2) returns "orange, grape".

場合separatornull、空の文字列 (String.Empty) 代わりに使用されます。If separator is null, an empty string (String.Empty) is used instead. 場合の任意の要素valuenull、空の文字列が代わりに使用されます。If any element in value is null, an empty string is used instead.

こちらもご覧ください

Join(Char, String[], Int32, Int32) Join(Char, String[], Int32, Int32) Join(Char, String[], Int32, Int32) Join(Char, String[], Int32, Int32)

public:
 static System::String ^ Join(char separator, cli::array <System::String ^> ^ value, int startIndex, int count);
public static string Join (char separator, string[] value, int startIndex, int count);
static member Join : char * string[] * int * int -> string
Public Shared Function Join (separator As Char, value As String(), startIndex As Integer, count As Integer) As String

パラメーター

separator
Char Char Char Char
value
String[]
startIndex
Int32 Int32 Int32 Int32

戻り値

Join(String, String[]) Join(String, String[]) Join(String, String[]) Join(String, String[])

文字列配列のすべての要素を連結します。各要素の間には、指定した区切り記号が挿入されます。Concatenates all the elements of a string array, using the specified separator between each element.

public:
 static System::String ^ Join(System::String ^ separator, ... cli::array <System::String ^> ^ value);
public static string Join (string separator, params string[] value);
static member Join : string * string[] -> string
Public Shared Function Join (separator As String, ParamArray value As String()) As String

パラメーター

separator
String String String String

区切り記号として使用する文字列。The string to use as a separator. value が 2 つ以上の要素を含む場合のみ、separator が返される文字列に含まれます。separator is included in the returned string only if value has more than one element.

value
String[]

連結する要素を格納している配列。An array that contains the elements to concatenate.

戻り値

value 内の要素からなる、separator 文字列で区切られた文字列。A string that consists of the elements in value delimited by the separator string. value が空の配列の場合、メソッドは Empty を返します。If value is an empty array, the method returns Empty.

例外

次の例で、Joinメソッド。The following example demonstrates the Join method.

using namespace System;
String^ MakeLine( int initVal, int multVal, String^ sep )
{
   array<String^>^sArr = gcnew array<String^>(10);
   for ( int i = initVal; i < initVal + 10; i++ )
      sArr[ i - initVal ] = String::Format( "{0, -3}", i * multVal );
   return String::Join( sep, sArr );
}

int main()
{
   Console::WriteLine( MakeLine( 0, 5, ", " ) );
   Console::WriteLine( MakeLine( 1, 6, "  " ) );
   Console::WriteLine( MakeLine( 9, 9, ": " ) );
   Console::WriteLine( MakeLine( 4, 7, "< " ) );
}
// The example displays the following output:
//       0  , 5  , 10 , 15 , 20 , 25 , 30 , 35 , 40 , 45
//       6    12   18   24   30   36   42   48   54   60
//       81 : 90 : 99 : 108: 117: 126: 135: 144: 153: 162
//       28 < 35 < 42 < 49 < 56 < 63 < 70 < 77 < 84 < 91
using System;

public class JoinTest {
    public static void Main() {

        Console.WriteLine(MakeLine(0, 5, ", "));
        Console.WriteLine(MakeLine(1, 6, "  "));
        Console.WriteLine(MakeLine(9, 9, ": "));
        Console.WriteLine(MakeLine(4, 7, "< "));
    }

    private static string MakeLine(int initVal, int multVal, string sep) {

        string [] sArr = new string [10];

        for (int i = initVal; i < initVal + 10; i++)
            sArr[i - initVal] = String.Format("{0,-3}", i * multVal);

        return String.Join(sep, sArr);
    }
}
// The example displays the following output:
//       0  , 5  , 10 , 15 , 20 , 25 , 30 , 35 , 40 , 45
//       6    12   18   24   30   36   42   48   54   60
//       81 : 90 : 99 : 108: 117: 126: 135: 144: 153: 162
//       28 < 35 < 42 < 49 < 56 < 63 < 70 < 77 < 84 < 91  
Imports System

Public Class JoinTest
    
    Public Shared Sub Main()
        
        Console.WriteLine(MakeLine(0, 5, ", "))
        Console.WriteLine(MakeLine(1, 6, "  "))
        Console.WriteLine(MakeLine(9, 9, ": "))
        Console.WriteLine(MakeLine(4, 7, "< "))
    End Sub 'Main
    
    
    Private Shared Function MakeLine(initVal As Integer, multVal As Integer, sep As String) As String
        Dim sArr(10) As String
        Dim i As Integer
        
        
        For i = initVal To (initVal + 10) - 1
            sArr((i - initVal)) = [String].Format("{0,-3}", i * multVal)
        
        Next i
        Return [String].Join(sep, sArr)
    End Function 'MakeLine
End Class 'JoinTest
' The example displays the following output:
'       0  , 5  , 10 , 15 , 20 , 25 , 30 , 35 , 40 , 45
'       6    12   18   24   30   36   42   48   54   60
'       81 : 90 : 99 : 108: 117: 126: 135: 144: 153: 162
'       28 < 35 < 42 < 49 < 56 < 63 < 70 < 77 < 84 < 91

注釈

たとえば場合、separatorは「,」の要素がvalueは、"apple"、「オレンジ」、"grape"および"pear" Join(separator, value) 「apple、orange、grape、pear」を返します。For example, if separator is ", " and the elements of value are "apple", "orange", "grape", and "pear", Join(separator, value) returns "apple, orange, grape, pear".

場合separatornull、空の文字列 (String.Empty) 代わりに使用されます。If separator is null, an empty string (String.Empty) is used instead. 場合の任意の要素valuenull、空の文字列が代わりに使用されます。If any element in value is null, an empty string is used instead.

こちらもご覧ください

Join(Char, Object[]) Join(Char, Object[]) Join(Char, Object[]) Join(Char, Object[])

public:
 static System::String ^ Join(char separator, ... cli::array <System::Object ^> ^ values);
public static string Join (char separator, params object[] values);
static member Join : char * obj[] -> string
Public Shared Function Join (separator As Char, ParamArray values As Object()) As String

パラメーター

separator
Char Char Char Char
values
Object[]

戻り値

Join(String, IEnumerable<String>) Join(String, IEnumerable<String>) Join(String, IEnumerable<String>) Join(String, IEnumerable<String>)

IEnumerable<T> 型の構築された String コレクションのメンバーを連結します。各メンバーの間には、指定した区切り記号が挿入されます。Concatenates the members of a constructed IEnumerable<T> collection of type String, using the specified separator between each member.

public:
 static System::String ^ Join(System::String ^ separator, System::Collections::Generic::IEnumerable<System::String ^> ^ values);
[System.Runtime.InteropServices.ComVisible(false)]
public static string Join (string separator, System.Collections.Generic.IEnumerable<string> values);
static member Join : string * seq<string> -> string
Public Shared Function Join (separator As String, values As IEnumerable(Of String)) As String

パラメーター

separator
String String String String

区切り記号として使用する文字列。separatorThe string to use as a separator.separator が返される文字列に含まれるのは、values が 2 つ以上の要素を含む場合に限られます。is included in the returned string only if values has more than one element.

values
IEnumerable<String>

連結する文字列を格納しているコレクション。A collection that contains the strings to concatenate.

戻り値

values のメンバーからなる、separator 文字列で区切られた文字列。A string that consists of the members of values delimited by the separator string. values にメンバーがない場合、メソッドは Empty を返します。If values has no members, the method returns Empty.

例外

次の例では、エラトステネスの篩というアルゴリズムを使用して、100 小さい素数を計算します。The following example uses the Sieve of Eratosthenes algorithm to calculate the prime numbers that are less than or equal to 100. 結果を割り当てます、List<T>型のオブジェクトString、しに渡されます、Join(String, IEnumerable<String>)メソッド。It assigns the result to a List<T> object of type String, which it then passes to the Join(String, IEnumerable<String>) method.

using System;
using System.Collections.Generic;

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

   private static List<int> GetPrimes(int maxPrime)
   {
      Array values = Array.CreateInstance(typeof(int), 
                              new int[] { maxPrime - 1}, new int[] { 2 });
      // Use Sieve of Eratosthenes 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<int> primes = new List<int>();
      for (int ctr = values.GetLowerBound(0); ctr <= values.GetUpperBound(0); ctr++)
         if ((int) values.GetValue(ctr) == 0) 
            primes.Add(ctr);
      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
Imports System.Collections.Generic

Module Example
   Public Sub Main()
      Dim maxPrime As Integer = 100
      Dim primes As List(Of String) = GetPrimes(maxPrime)
      Console.WriteLine("Primes less than {0}:", maxPrime)
      Console.WriteLine("   {0}", String.Join(" ", primes))
   End Sub
   
   Private Function GetPrimes(maxPrime As Integer) As List(Of String)
      Dim values As Array = Array.CreateInstance(GetType(Integer), _
                              New Integer() { maxPrime - 1}, New Integer(){ 2 }) 
        ' Use Sieve of Eratosthenes 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

注釈

場合separatornull、空の文字列 (String.Empty) 代わりに使用されます。If separator is null, an empty string (String.Empty) is used instead. 場合のメンバーはすべてvaluesnull、空の文字列が代わりに使用されます。If any member of values is null, an empty string is used instead.

Join(String, IEnumerable<String>) 便利なメソッド内の各要素を連結することができますが、IEnumerable(Of String)文字列配列に要素を変換しなくてもコレクション。Join(String, IEnumerable<String>) is a convenience method that lets you concatenate each element in an IEnumerable(Of String) collection without first converting the elements to a string array. 統合言語クエリ (LINQ) のクエリ式で特に便利です。It is particularly useful with Language-Integrated Query (LINQ) query expressions. 次の例では、List(Of String)と等しいか (つまり、例では、"M")、特定の文字を超える文字を選択するラムダ式にアルファベットの大文字または小文字の文字を含むオブジェクト。The following example passes a List(Of String) object that contains either the uppercase or lowercase letters of the alphabet to a lambda expression that selects letters that are equal to or greater than a particular letter (which, in the example, is "M"). IEnumerable(Of String)によって返されるコレクション、Enumerable.Whereにメソッドが渡される、Join(String, IEnumerable<String>)メソッドを 1 つの文字列として結果を表示します。The IEnumerable(Of String) collection returned by the Enumerable.Where method is passed to the Join(String, IEnumerable<String>) method to display the result as a single string.

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

public class Example
{
   public static void Main()
   {
      string output = String.Join(" ", 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(Convert.ToChar(charValue + ctr).ToString());
      return alphabet; 
   }
}
// The example displays the following output:
//      M N O P Q R S T U V W X Y Z
Imports System.Collections.Generic
Imports System.Linq

Module modMain
   Public Sub Main()
      Dim output As String = String.Join(" ", 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:
'      M N O P Q R S T U V W X Y Z
こちらもご覧ください

Join(String, Object[]) Join(String, Object[]) Join(String, Object[]) Join(String, Object[])

オブジェクト配列の要素を連結します。各要素の間には、指定した区切り記号が挿入されます。Concatenates the elements of an object array, using the specified separator between each element.

public:
 static System::String ^ Join(System::String ^ separator, ... cli::array <System::Object ^> ^ values);
[System.Runtime.InteropServices.ComVisible(false)]
public static string Join (string separator, params object[] values);
static member Join : string * obj[] -> string
Public Shared Function Join (separator As String, ParamArray values As Object()) As String

パラメーター

separator
String String String String

区切り記号として使用する文字列。The string to use as a separator. values が 2 つ以上の要素を含む場合のみ、separator が返される文字列に含まれます。separator is included in the returned string only if values has more than one element.

values
Object[]

連結する要素を格納している配列。An array that contains the elements to concatenate.

戻り値

values の要素からなる、separator 文字列で区切られた文字列。A string that consists of the elements of values delimited by the separator string. values が空の配列の場合、メソッドは Empty を返します。If values is an empty array, the method returns Empty.

例外

次の例では、エラトステネスの篩というアルゴリズムを使用して、100 小さい素数を計算します。The following example uses the Sieve of Eratosthenes algorithm to calculate the prime numbers that are less than or equal to 100. 結果を次に、渡します、整数の配列に代入、Join(String, Object[])メソッド。It assigns the result to a integer array, which it then passes to the Join(String, Object[]) method.

using System;
using System.Collections.Generic;

public class Example
{
   public static void Main()
   {
      int maxPrime = 100;
      int[] primes = GetPrimes(maxPrime);
      Console.WriteLine("Primes less than {0}:", maxPrime);
      Console.WriteLine("   {0}", String.Join(" ", primes));
   }

   private static int[] GetPrimes(int maxPrime)
   {
      Array values = Array.CreateInstance(typeof(int), 
                              new int[] { maxPrime - 1}, new int[] { 2 }); 
      // Use Sieve of Eratosthenes 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<int> primes = new List<int>();
      for (int ctr = values.GetLowerBound(0); ctr <= values.GetUpperBound(0); ctr++)
         if ((int) values.GetValue(ctr) == 0) 
            primes.Add(ctr);
      return primes.ToArray();
   }   
}
// 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
Module Example
   Public Sub Main()
      Dim maxPrime As Integer = 100
      Dim primes() As Integer = GetPrimes(maxPrime)
      Console.WriteLine("Primes less than {0}:", maxPrime)
      Console.WriteLine("   {0}", String.Join(" ", primes))
   End Sub
   
   Private Function GetPrimes(maxPrime As Integer) As Integer()
      Dim values As Array = Array.CreateInstance(GetType(Integer), _
                              New Integer() { maxPrime - 1}, New Integer(){ 2 }) 
        ' Use Sieve of Eratosthenes 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 System.Collections.Generic.List(Of Integer)
      For ctr As Integer = values.GetLowerBound(0) To values.GetUpperBound(0)
         If CInt(values.GetValue(ctr)) = 0 Then primes.Add(ctr)
      Next            
      Return primes.ToArray()
   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

注釈

場合separatornull場合、または任意の要素のvalues以外の最初の要素はnull、空の文字列 (String.Empty) 代わりに使用されます。If separator is null or if any element of values other than the first element is null, an empty string (String.Empty) is used instead. 場合は、呼び出し元のセクションのノートを参照して、最初の要素のvaluesnullSee the Notes for Callers section if the first element of values is null.

Join(String, Object[]) 文字列をその要素を明示的に変換しなくてもオブジェクト配列内の各要素を連結することができます便利な方法です。Join(String, Object[]) is a convenience method that lets you concatenate each element in an object array without explicitly converting its elements to strings. 配列内の各オブジェクトの文字列表現を呼び出して、そのオブジェクトの派生ToStringメソッド。The string representation of each object in the array is derived by calling that object's ToString method.

注意 (呼び出し元)

場合の最初の要素valuesnullJoin(String, Object[])メソッドが内の要素を連結しないvalues代わりに返されますが、Emptyします。If the first element of values is null, the Join(String, Object[]) method does not concatenate the elements in values but instead returns Empty. この問題の回避策数を利用できます。A number of workarounds for this issue are available. 値を割り当てるには、最も簡単なEmpty配列の最初の要素を次の例として示します。The easiest is to assign a value of Empty to the first element of the array, as the following example shows.

[!code-csharpSystem.String.Join#6] [!code-vbSystem.String.Join#6][!code-csharpSystem.String.Join#6] [!code-vbSystem.String.Join#6]

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Join(Char, String[]) Join(Char, String[]) Join(Char, String[]) Join(Char, String[])

public:
 static System::String ^ Join(char separator, ... cli::array <System::String ^> ^ value);
public static string Join (char separator, params string[] value);
static member Join : char * string[] -> string
Public Shared Function Join (separator As Char, ParamArray value As String()) As String

パラメーター

separator
Char Char Char Char
value
String[]

戻り値

Join<T>(Char, IEnumerable<T>) Join<T>(Char, IEnumerable<T>) Join<T>(Char, IEnumerable<T>) Join<T>(Char, IEnumerable<T>)

public:
generic <typename T>
 static System::String ^ Join(char separator, System::Collections::Generic::IEnumerable<T> ^ values);
public static string Join<T> (char separator, System.Collections.Generic.IEnumerable<T> values);
static member Join : char * seq<'T> -> string
Public Shared Function Join(Of T) (separator As Char, values As IEnumerable(Of T)) As String

型パラメーター

T

パラメーター

separator
Char Char Char Char

戻り値

Join<T>(String, IEnumerable<T>) Join<T>(String, IEnumerable<T>) Join<T>(String, IEnumerable<T>) Join<T>(String, IEnumerable<T>)

コレクションのメンバーを連結します。各メンバーの間には、指定した区切り記号が挿入されます。Concatenates the members of a collection, using the specified separator between each member.

public:
generic <typename T>
 static System::String ^ Join(System::String ^ separator, System::Collections::Generic::IEnumerable<T> ^ values);
[System.Runtime.InteropServices.ComVisible(false)]
public static string Join<T> (string separator, System.Collections.Generic.IEnumerable<T> values);
static member Join : string * seq<'T> -> string
Public Shared Function Join(Of T) (separator As String, values As IEnumerable(Of T)) As String

型パラメーター

T

values のメンバーの型。The type of the members of values.

パラメーター

separator
String String String String

区切り記号として使用する文字列。separatorThe string to use as a separator.separator が返される文字列に含まれるのは、values が 2 つ以上の要素を含む場合に限られます。is included in the returned string only if values has more than one element.

values
IEnumerable<T> IEnumerable<T> IEnumerable<T> IEnumerable<T>

連結するオブジェクトを格納しているコレクション。A collection that contains the objects to concatenate.

戻り値

values のメンバーからなる、separator 文字列で区切られた文字列。A string that consists of the members of values delimited by the separator string. values にメンバーがない場合、メソッドは Empty を返します。If values has no members, the method returns Empty.

例外

次の例では、エラトステネスの篩というアルゴリズムを使用して、100 小さい素数を計算します。The following example uses the Sieve of Eratosthenes algorithm to calculate the prime numbers that are less than or equal to 100. 結果を割り当てます、List<T>しに渡されます整数型のオブジェクト、Join<T>(String, IEnumerable<T>)メソッド。It assigns the result to a List<T> object of type integer, which it then passes to the Join<T>(String, IEnumerable<T>) method.

using System;
using System.Collections.Generic;

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

   private static List<int> GetPrimes(int maxPrime)
   {
      Array values = Array.CreateInstance(typeof(int), 
                              new int[] { maxPrime - 1}, new int[] { 2 });
      // Use Sieve of Eratosthenes 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<int> primes = new List<int>();
      for (int ctr = values.GetLowerBound(0); ctr <= values.GetUpperBound(0); ctr++)
         if ((int) values.GetValue(ctr) == 0) 
            primes.Add(ctr);
      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
Imports System.Collections.Generic

Module Example
   Public Sub Main()
      Dim maxPrime As Integer = 100
      Dim primes As List(Of Integer) = GetPrimes(maxPrime)
      Console.WriteLine("Primes less than {0}:", maxPrime)
      Console.WriteLine("   {0}", String.Join(" ", primes))
   End Sub
   
   Private Function GetPrimes(maxPrime As Integer) As List(Of Integer)
      Dim values As Array = Array.CreateInstance(GetType(Integer), _
                              New Integer() { maxPrime - 1}, New Integer(){ 2 }) 
        ' Use Sieve of Eratosthenes 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 System.Collections.Generic.List(Of Integer)
      For ctr As Integer = values.GetLowerBound(0) To values.GetUpperBound(0)
         If CInt(values.GetValue(ctr)) = 0 Then primes.Add(ctr)
      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

注釈

場合separatornull、空の文字列 (String.Empty) 代わりに使用されます。If separator is null, an empty string (String.Empty) is used instead. 場合のメンバーはすべてvaluesnull、空の文字列が代わりに使用されます。If any member of values is null, an empty string is used instead.

Join<T>(String, IEnumerable<T>) 便利なメソッドの各メンバーを連結することができますが、IEnumerable<T>最初を文字列に変換することがなくコレクション。Join<T>(String, IEnumerable<T>) is a convenience method that lets you concatenate each member of an IEnumerable<T> collection without first converting them to strings. 内の各オブジェクトの文字列表現、IEnumerable<T>呼び出して、そのオブジェクトのコレクションは派生ToStringメソッド。The string representation of each object in the IEnumerable<T> collection is derived by calling that object's ToString method.

このメソッドは、特定統合言語クエリ (LINQ) クエリ式で便利です。This method is particular useful with Language-Integrated Query (LINQ) query expressions. たとえば、次のコードは非常に単純な定義Animalanimal クラスとが所属する順序の名前を表すクラス。For example, the following code defines a very simple Animal class that contains the name of an animal and the order to which it belongs. 定義し、List<T>オブジェクトの数を含むAnimalオブジェクト。It then defines a List<T> object that contains a number of Animal objects. Enumerable.Whereを抽出する拡張メソッドが呼び出される、AnimalオブジェクトOrderプロパティが「げっ歯類」に等しい。The Enumerable.Where extension method is called to extract the Animal objects whose Order property equals "Rodent". 結果に渡される、Join<T>(String, IEnumerable<T>)メソッド。The result is passed to the Join<T>(String, IEnumerable<T>) method.

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.Join(" ", animals.Where( animal => 
                      (animal.Order == "Rodent")));
      Console.WriteLine(output);  
   }
}
// The example displays the following output:
//      Squirrel Capybara
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.Join(" ", animals.Where(Function(animal) _
                                           animal.Order = "Rodent"))
      Console.WriteLine(output)                                           
   End Sub
End Module
' The example displays the following output:
'      Squirrel Capybara
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