String.Concat 方法
定義
重要
部分資訊涉及發行前產品,在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊,不做任何明確或隱含的瑕疵擔保。
多載
Concat(String, String, String, String) |
串連 String的四個指定實例。 |
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(Object, Object, Object, Object) |
串連四個指定物件的字串表示,以及選擇性可變長度參數清單中指定的任何物件。 |
Concat(String, String, String) |
串連三個指定的實體 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) |
串連兩個指定的實體 String。 |
Concat(Object) |
建立指定物件的字串表示。 |
Concat(Object, Object) |
串連兩個指定物件的字串表示。 |
Concat(String[]) |
串連指定之 String 陣列的專案。 |
Concat(ReadOnlySpan<String>) |
串連指定範圍 String的專案。 |
Concat(ReadOnlySpan<Object>) |
串連指定之物件範圍中元素的字串表示。 |
Concat(Object[]) |
串連指定之 Object 陣列中元素的字串表示。 |
Concat(IEnumerable<String>) |
串連類型 String之建構 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>) |
串連 IEnumerable<T> 實作的成員。 |
備註
注意
您也可以使用語言的字串串連運算符,例如 C# 和 F# 中的 +
,或在 Visual Basic 中使用 &
和 +
串連字串串。 這兩個編譯程式會將串連運算符轉譯成對其中一個 多載的呼叫,String.Concat
。
Concat(String, String, String, String)
串連 String的四個指定實例。
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);
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
str0
、str1
、str2
和 str3
的串連。
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。 然後,它會呼叫 Concat(String, String, String, String) 方法來重新組合拼字。
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
方法會串連 str0
、str1
、str2
和 str3
;它不會新增任何分隔符。
另請參閱
適用於
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。
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
str0
、str1
、str2
和 str3
值的串連字串表示。
適用於
Concat(Object, Object, Object, Object)
重要
此 API 不符合 CLS 規範。
串連四個指定物件的字串表示,以及選擇性可變長度參數清單中指定的任何物件。
public:
static System::String ^ Concat(System::Object ^ arg0, System::Object ^ arg1, System::Object ^ arg2, System::Object ^ arg3);
[System.CLSCompliant(false)]
public static string Concat (object arg0, object arg1, object arg2, object arg3);
[<System.CLSCompliant(false)>]
static member Concat : obj * obj * obj * obj -> string
Public Shared Function Concat (arg0 As Object, arg1 As Object, arg2 As Object, arg3 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。
- arg3
- Object
要串連的第四個物件。
傳回
參數清單中每個值的串連字串表示。
- 屬性
範例
下列範例說明如何使用 Concat(Object, Object, Object, Object) 方法來串連變數參數清單。 在此情況下,會使用九個參數呼叫 方法。
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
注意
此 API 不符合 CLS 標準。 符合 CLS 標準的替代方案 String.Concat(Object[])。 C# 和 Visual Basic 編譯程式會自動解析對此方法的呼叫,以呼叫 String.Concat(Object[])。
方法會藉由呼叫其無參數 ToString
方法,串連參數清單中的每個物件;它不會新增任何分隔符。
String.Empty 用來取代任何 null 自變數。
注意
Concat 方法的最後一個參數是一或多個要串連之其他對象的選擇性逗號分隔清單。
給呼叫者的注意事項
這個方法會以 vararg
關鍵詞標示,這表示它支援變數數目的參數。 方法可以從 Visual C++呼叫,但無法從 C# 或 Visual Basic 程式代碼呼叫。 C# 和 Visual Basic 編譯程式會將對 Concat(Object, Object, Object, Object) 的呼叫解析為對 Concat(Object[])的呼叫。
適用於
Concat(String, String, String)
串連三個指定的實體 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);
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
str0
、str1
和 str2
的串連。
範例
下列範例會使用 Concat 方法來串連三個字串並顯示結果。
using namespace System;
void main()
{
String^ s1 = "We went to a bookstore, ";
String^ s2 = "a movie, ";
String^ s3 = "and a restaurant.";
String^ 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.
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
方法會串連 str0
、str1
和 str2
;它不會新增任何分隔符。
另請參閱
適用於
Concat(ReadOnlySpan<Char>, ReadOnlySpan<Char>, ReadOnlySpan<Char>)
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
str0
、str1
和 str2
值的串連字串表示。
適用於
Concat(Object, Object, Object)
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);
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
arg0
、arg1
和 arg2
值的串連字串表示。
範例
下列範例示範 Concat 方法。
using namespace System;
int main()
{
int i = -123;
Object^ o = i;
array<Object^>^objs = { -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
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
方法會呼叫每個物件的無參數 ToString
方法,以串連 arg0
、arg1
和 arg2
:它不會新增任何分隔符。
String.Empty 用來取代任何 null 自變數。
另請參閱
適用於
Concat(String, String)
串連兩個指定的實體 String。
public:
static System::String ^ Concat(System::String ^ str0, System::String ^ str1);
public static string Concat (string str0, 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
str0
和 str1
的串連。
範例
下列範例會串連人員的第一個、中間和姓氏。
using namespace System;
int 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 = String::Concat( " ", mName->Trim() );
lName = String::Concat( " ", 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'!
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
方法會串連 str0
和 str1
;它不會新增任何分隔符。
Empty 字串會用來取代任何 null 自變數。
另請參閱
適用於
Concat(Object)
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);
public static string Concat (object? arg0);
static member Concat : obj -> string
Public Shared Function Concat (arg0 As Object) As String
參數
- arg0
- Object
要表示的物件,或 null
。
傳回
arg0
值的字串表示,如果 arg0
為 null
,則為 Empty。
範例
下列範例示範 Concat 方法。
using namespace System;
int main()
{
int i = -123;
Object^ o = i;
array<Object^>^objs = { -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
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
Concat(Object) 方法會呼叫無參數 ToString
方法,以字串表示 arg0
。
另請參閱
適用於
Concat(Object, Object)
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);
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
arg0
和 arg1
值的串連字串表示。
範例
下列範例示範 Concat 方法。
using namespace System;
int main()
{
int i = -123;
Object^ o = i;
array<Object^>^objs = { -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
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
方法會藉由呼叫無 ToString
參數的 arg0
和 arg1
方法串連 arg0
和 arg1
;它不會新增任何分隔符。
String.Empty 用來取代任何 null 自變數。
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
適用於
Concat(String[])
重要
此 API 不符合 CLS 規範。
串連指定之 String 陣列的專案。
public:
static System::String ^ Concat(... cli::array <System::String ^> ^ values);
public static string Concat (params string[] values);
public static string Concat (params string?[] values);
[System.CLSCompliant(false)]
public static string Concat (params string[] values);
static member Concat : string[] -> string
[<System.CLSCompliant(false)>]
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
values
的串連專案。
- 屬性
例外狀況
values
null
。
記憶體不足。
範例
下列範例示範搭配 String 陣列使用 Concat 方法。
using namespace System;
int main()
{
// Make an array of strings. Note that we have included spaces.
array<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
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
方法會串連 values
中的每個物件;它不會新增任何分隔符。
會使用 Empty 字串來取代數位中的任何 Null 物件。
另請參閱
適用於
Concat(ReadOnlySpan<String>)
串連指定範圍 String的專案。
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>
String 實例範圍。
傳回
values
的串連專案。
適用於
Concat(ReadOnlySpan<Object>)
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
args
中專案值的串連字串表示。
適用於
Concat(Object[])
串連指定之 Object 陣列中元素的字串表示。
public:
static System::String ^ Concat(... cli::array <System::Object ^> ^ args);
public static string Concat (params 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
args
中專案值的串連字串表示。
例外狀況
args
null
。
記憶體不足。
範例
下列範例示範搭配 Object 陣列使用 Concat 方法。
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
方法會藉由呼叫該物件的無參數 ToString
方法,串連 args
中的每個物件;它不會新增任何分隔符。
String.Empty 會用來取代陣列中的任何 Null 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++編譯程式會解析對具有四個以上對象參數之 Concat 的呼叫,做為對 Concat(Object, Object, Object, Object)的呼叫。
另請參閱
適用於
Concat(IEnumerable<String>)
串連類型 String之建構 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);
public static string Concat (System.Collections.Generic.IEnumerable<string?> values);
[System.Runtime.InteropServices.ComVisible(false)]
public static string Concat (System.Collections.Generic.IEnumerable<string> values);
static member Concat : seq<string> -> string
[<System.Runtime.InteropServices.ComVisible(false)>]
static member Concat : seq<string> -> string
Public Shared Function Concat (values As IEnumerable(Of String)) As String
參數
- values
- IEnumerable<String>
實作 IEnumerable<T> 且泛型型別自變數為 String的集合物件。
傳回
values
中的串連字串,如果 values
是空的 IEnumerable(Of String)
,則為 Empty。
- 屬性
例外狀況
values
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。 它會將結果指派給類型為 StringList<T> 對象,然後傳遞給 Concat(IEnumerable<String>) 方法。
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
方法會串連 values
中的每個物件;它不會新增任何分隔符。 若要指定 values
每個成員之間的分隔符,請呼叫 Join(String, IEnumerable<String>) 方法。
Empty 字串會用來取代 values
中的任何 null 專案。
如果 values
是空的 IEnumerable(Of String)
,則方法會傳回 String.Empty。 如果 values
是 null
,則方法會擲回 ArgumentNullException 例外狀況。
Concat(IEnumerable<String>) 是一種方便的方法,可讓您串連 IEnumerable(Of String)
集合中的每個專案,而不需要先將項目轉換成字串陣列。 它特別適用於 Language-Integrated Query (LINQ) 查詢表達式。 下列範例會將包含字母大寫或小寫字母的 List(Of String)
對象傳遞至 Lambda 運算式,該表達式會選取等於或大於特定字母的字母(在此範例中為 “M” )。
Enumerable.Where 方法傳回的 IEnumerable(Of String)
集合會傳遞至 Concat(IEnumerable<String>) 方法,以將結果顯示為單一字串。
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
適用於
Concat(ReadOnlySpan<Char>, ReadOnlySpan<Char>)
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
str0
和 str1
值的串連字串表示。
適用於
Concat<T>(IEnumerable<T>)
串連 IEnumerable<T> 實作的成員。
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);
[System.Runtime.InteropServices.ComVisible(false)]
public static string Concat<T> (System.Collections.Generic.IEnumerable<T> values);
static member Concat : seq<'T> -> string
[<System.Runtime.InteropServices.ComVisible(false)>]
static member Concat : seq<'T> -> string
Public Shared Function Concat(Of T) (values As IEnumerable(Of T)) As String
類型參數
- T
values
的成員類型。
參數
- values
- IEnumerable<T>
實作 IEnumerable<T> 介面的集合物件。
傳回
values
中的串連成員。
- 屬性
例外狀況
values
null
。
範例
下列範例會定義非常簡單的 Animal
類別,其中包含動物的名稱及其所屬的順序。 然後,它會定義 List<T> 物件,以包含一些 Animal
物件。 呼叫 Enumerable.Where 擴充方法,以擷取 Order
屬性等於 “Rodent” 的 Animal
物件。 結果會傳遞至 Concat<T>(IEnumerable<T>) 方法,並顯示至主控台。
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
方法會串連 values
中的每個物件;它不會新增任何分隔符。
Empty 字串會用來取代任何 null 自變數。
Concat<T>(IEnumerable<T>) 是一種便利的方法,可讓您串連 IEnumerable<T> 集合中的每個專案,而不需要先將項目轉換成字串。 如範例所示,它特別適用於 Language-Integrated Query (LINQ) 查詢表達式。
IEnumerable<T> 集合中每個物件的字串表示,是藉由呼叫該物件的 ToString
方法來衍生。