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(Char, Object[]) Join(Char, Object[]) Join(Char, Object[]) Join(Char, Object[])
Join(Char, String[]) Join(Char, String[]) Join(Char, String[]) Join(Char, String[])
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(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, String[], Int32, Int32) Join(Char, String[], Int32, Int32) Join(Char, String[], Int32, Int32) Join(Char, String[], Int32, Int32)
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<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(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(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(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、ありアルゴリズムのエラトステネスを使用して、100以下の素数を計算します。The following example uses the Sieve of Eratosthenes algorithm to calculate the prime numbers that are less than or equal to 100. 結果を型List<T> Stringのオブジェクトに代入し、次にJoin(String, IEnumerable<String>)メソッドに渡します。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

String.Emptyseparator の場合は、代わりに空の文字列()が使用されます。nullIf separator is null, an empty string (String.Empty) is used instead. のいずれかのvaluesメンバー nullがの場合は、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>)は、要素を最初に文字列配列に変換せずIEnumerable(Of String)に、コレクション内の各要素を連結できる便利なメソッドです。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. これは、統合言語クエリ (LINQ) 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) 、アルファベットの大文字または小文字を含むオブジェクトを、特定の文字以上の文字 (例では "M") を選択するラムダ式に渡します。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"). メソッドによって返されるIEnumerable(Of String)コレクションは、結果を1つの文字列として表示するためにメソッドに渡されます。Join(String, IEnumerable<String>) Enumerable.WhereThe 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
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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、ありアルゴリズムのエラトステネスを使用して、100以下の素数を計算します。The following example uses the Sieve of Eratosthenes algorithm to calculate the prime numbers that are less than or equal to 100. 結果を整数の配列に代入し、次にJoin(String, Object[])メソッドに渡します。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

separator values nullString.Emptyの場合、または最初の要素以外のの要素がの場合は、代わりに空の文字列 () が使用されます。 nullIf separator is null or if any element of values other than the first element is null, an empty string (String.Empty) is used instead. の最初の要素がvalues nullの場合は、「呼び出し元のメモ」セクションを参照してください。See the Notes for Callers section if the first element of values is null.

Join(String, Object[])は、要素を文字列に明示的に変換せずに、オブジェクト配列内の各要素を連結できる便利なメソッドです。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形式は、そのオブジェクトのToStringメソッドを呼び出すことによって派生されます。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)

の最初の要素がvalues nullの場合、 Join(String, Object[])メソッドはの要素を連結せvaluesずに、 Emptyを返します。If the first element of values is null, the Join(String, Object[]) method does not concatenate the elements in values but instead returns Empty. この問題の回避策は多数あります。A number of workarounds for this issue are available. 最も簡単な方法は、次のEmpty例に示すように、配列の最初の要素に値を代入することです。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(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, string[] value);
static member Join : string * string[] -> string
Public Shared Function Join (separator As String, 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

メソッドのJoin例を次に示します。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  
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
    
    
    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、が " separator ," で、のvalue要素が "apple"、"オレンジ"、"grape"、 Join(separator, value)および "pear" の場合、は "apple, オレンジ, 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".

String.Emptyseparator の場合は、代わりに空の文字列()が使用されます。nullIf separator is null, an empty string (String.Empty) is used instead. 内のvalueいずれかのnull要素がの場合は、代わりに空の文字列が使用されます。If any element in value is null, an empty string is used instead.

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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[], 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、果物という名前の配列の2つの要素を連結しています。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'
*/
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、が " separator ," で、のvalue要素が "apple"、"オレンジ"、"grape"、 Join(separator, value, 1, 2)および "pear" の場合、は "オレンジ, grape" を返します。For example, if separator is ", " and the elements of value are "apple", "orange", "grape", and "pear", Join(separator, value, 1, 2) returns "orange, grape".

String.Emptyseparator の場合は、代わりに空の文字列()が使用されます。nullIf separator is null, an empty string (String.Empty) is used instead. 内のvalueいずれかのnull要素がの場合は、代わりに空の文字列が使用されます。If any element in value is null, an empty string is used instead.

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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、ありアルゴリズムのエラトステネスを使用して、100以下の素数を計算します。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 integer 型のList<T>オブジェクトに代入し、次Join<T>(String, IEnumerable<T>)にメソッドに渡します。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

String.Emptyseparator の場合は、代わりに空の文字列()が使用されます。nullIf separator is null, an empty string (String.Empty) is used instead. のいずれかのvaluesメンバー nullがの場合は、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>)は、最初にIEnumerable<T>コレクションの各メンバーを文字列に変換せずに連結できる便利なメソッドです。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. IEnumerable<T>コレクション内の各オブジェクトの文字列形式は、そのオブジェクトのToStringメソッドを呼び出すことによって派生されます。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、統合言語クエリ (LINQ) クエリ式で特に便利です。This method is particular useful with Language-Integrated Query (LINQ) query expressions. たとえば、次のコードでは、動物のAnimal名前とそれが属する順序を含む非常に単純なクラスを定義しています。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. 次に、多数List<T>Animalオブジェクトを含むオブジェクトを定義します。It then defines a List<T> object that contains a number of Animal objects. 拡張Enumerable.Whereメソッドは、 Orderプロパティが "げっ歯類Animal " と等しいオブジェクトを抽出するために呼び出されます。The Enumerable.Where extension method is called to extract the Animal objects whose Order property equals "Rodent". 結果はJoin<T>(String, IEnumerable<T>)メソッドに渡されます。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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適用対象