String.GetEnumerator Methode
Definition
Wichtig
Einige Informationen beziehen sich auf Vorabversionen, die vor dem Release ggf. grundlegend überarbeitet werden. Microsoft übernimmt hinsichtlich der hier bereitgestellten Informationen keine Gewährleistungen, seien sie ausdrücklich oder konkludent.
Ruft ein Objekt ab, das die einzelnen Zeichen dieser Zeichenfolge durchlaufen kann.
public:
CharEnumerator ^ GetEnumerator();public CharEnumerator GetEnumerator ();member this.GetEnumerator : unit -> CharEnumeratorPublic Function GetEnumerator () As CharEnumeratorGibt zurück
Ein Enumeratorobjekt.
Beispiele
Im folgenden Beispiel werden die Zeichen in mehreren Zeichenfolgen durchläuft und Informationen zu ihren einzelnen Zeichen angezeigt. Es verwendet das Sprachiterationskonstrukt anstelle eines Aufrufs der GetEnumerator -Methode.
using namespace System;
void EnumerateAndDisplay(String^ phrase)
{
Console::WriteLine("The characters in the string \"{0}\" are:",
phrase);
int CharCount = 0;
int controlChars = 0;
int alphanumeric = 0;
int punctuation = 0;
for each (Char ch in phrase) {
Console::Write("'{0}' ", (! Char::IsControl(ch)) ? ch.ToString() :
"0x" + Convert::ToUInt16(ch).ToString("X4"));
if (Char::IsLetterOrDigit(ch))
alphanumeric++;
else if (Char::IsControl(ch))
controlChars++;
else if (Char::IsPunctuation(ch))
punctuation++;
CharCount++;
}
Console::WriteLine("\n Total characters: {0,3}", CharCount);
Console::WriteLine(" Alphanumeric characters: {0,3}", alphanumeric);
Console::WriteLine(" Punctuation characters: {0,3}", punctuation);
Console::WriteLine(" Control Characters: {0,3}\n", controlChars);
}
int main()
{
EnumerateAndDisplay("Test Case");
EnumerateAndDisplay("This is a sentence.");
EnumerateAndDisplay("Has\ttwo\ttabs");
EnumerateAndDisplay("Two\nnew\nlines");
}
// The example displays the following output:
// The characters in the string "Test Case" are:
// 'T' 'e' 's' 't' ' ' 'C' 'a' 's' 'e'
// Total characters: 9
// Alphanumeric characters: 8
// Punctuation characters: 0
// Control Characters: 0
//
// The characters in the string "This is a sentence." are:
// 'T' 'h' 'i' 's' ' ' 'i' 's' ' ' 'a' ' ' 's' 'e' 'n' 't' 'e' 'n' 'c' 'e' '.'
// Total characters: 19
// Alphanumeric characters: 15
// Punctuation characters: 1
// Control Characters: 0
//
// The characters in the string "Has two tabs" are:
// 'H' 'a' 's' '0x0009' 't' 'w' 'o' '0x0009' 't' 'a' 'b' 's'
// Total characters: 12
// Alphanumeric characters: 10
// Punctuation characters: 0
// Control Characters: 2
//
// The characters in the string "Two
// new
// lines" are:
// 'T' 'w' 'o' '0x000A' 'n' 'e' 'w' '0x000A' 'l' 'i' 'n' 'e' 's'
// Total characters: 13
// Alphanumeric characters: 11
// Punctuation characters: 0
// Control Characters: 2
using System;
class Example
{
public static void Main()
{
EnumerateAndDisplay("Test Case");
EnumerateAndDisplay("This is a sentence.");
EnumerateAndDisplay("Has\ttwo\ttabs" );
EnumerateAndDisplay("Two\nnew\nlines");
}
static void EnumerateAndDisplay(String phrase)
{
Console.WriteLine("The characters in the string \"{0}\" are:",
phrase);
int CharCount = 0;
int controlChars = 0;
int alphanumeric = 0;
int punctuation = 0;
foreach (var ch in phrase) {
Console.Write(Char.IsControl(ch) ? $"{ch}" : $"0x{(ushort)ch:X4}");
if (Char.IsLetterOrDigit(ch))
alphanumeric++;
else if (Char.IsControl(ch))
controlChars++;
else if (Char.IsPunctuation(ch))
punctuation++;
CharCount++;
}
Console.WriteLine("\n Total characters: {0,3}", CharCount);
Console.WriteLine(" Alphanumeric characters: {0,3}", alphanumeric);
Console.WriteLine(" Punctuation characters: {0,3}", punctuation);
Console.WriteLine(" Control Characters: {0,3}\n", controlChars);
}
}
// The example displays the following output:
// The characters in the string "Test Case" are:
// 'T' 'e' 's' 't' ' ' 'C' 'a' 's' 'e'
// Total characters: 9
// Alphanumeric characters: 8
// Punctuation characters: 0
// Control Characters: 0
//
// The characters in the string "This is a sentence." are:
// 'T' 'h' 'i' 's' ' ' 'i' 's' ' ' 'a' ' ' 's' 'e' 'n' 't' 'e' 'n' 'c' 'e' '.'
// Total characters: 19
// Alphanumeric characters: 15
// Punctuation characters: 1
// Control Characters: 0
//
// The characters in the string "Has two tabs" are:
// 'H' 'a' 's' '0x0009' 't' 'w' 'o' '0x0009' 't' 'a' 'b' 's'
// Total characters: 12
// Alphanumeric characters: 10
// Punctuation characters: 0
// Control Characters: 2
//
// The characters in the string "Two
// new
// lines" are:
// 'T' 'w' 'o' '0x000A' 'n' 'e' 'w' '0x000A' 'l' 'i' 'n' 'e' 's'
// Total characters: 13
// Alphanumeric characters: 11
// Punctuation characters: 0
// Control Characters: 2
Module Example
Sub Main()
EnumerateAndDisplay("Test Case")
EnumerateAndDisplay("This is a sentence.")
EnumerateAndDisplay("Has" & vbTab & "two" & vbTab & "tabs")
EnumerateAndDisplay("Two" & vbLf & "new" & vbLf & "lines")
End Sub
Sub EnumerateAndDisplay(phrase As String)
Console.WriteLine("The characters in the string ""{0}"" are:", phrase)
Dim charCount As Integer = 0
Dim controlChars As Integer = 0
Dim alphanumeric As Integer = 0
Dim punctuation As Integer = 0
For Each ch In phrase
Console.Write("'{0}' ", If(Not Char.IsControl(ch), ch,
"0x" + Convert.ToUInt16(ch).ToString("X4")))
If Char.IsLetterOrDigit(ch) Then
alphanumeric += 1
Else If Char.IsControl(ch) Then
controlChars += 1
Else If Char.IsPunctuation(ch) Then
punctuation += 1
End If
CharCount += 1
Next
Console.WriteLine()
Console.WriteLine(" Total characters: {0,3}", CharCount)
Console.WriteLine(" Alphanumeric characters: {0,3}", alphanumeric)
Console.WriteLine(" Punctuation characters: {0,3}", punctuation)
Console.WriteLine(" Control Characters: {0,3}", controlChars)
Console.WriteLine()
End Sub
End Module
' This example displays the following output:
' The characters in the string "Test Case" are:
' 'T' 'e' 's' 't' ' ' 'C' 'a' 's' 'e'
' Total characters: 9
' Alphanumeric characters: 8
' Punctuation characters: 0
' Control Characters: 0
'
' The characters in the string "This is a sentence." are:
' 'T' 'h' 'i' 's' ' ' 'i' 's' ' ' 'a' ' ' 's' 'e' 'n' 't' 'e' 'n' 'c' 'e' '.'
' Total characters: 19
' Alphanumeric characters: 15
' Punctuation characters: 1
' Control Characters: 0
'
' The characters in the string "Has two tabs" are:
' 'H' 'a' 's' '0x0009' 't' 'w' 'o' '0x0009' 't' 'a' 'b' 's'
' Total characters: 12
' Alphanumeric characters: 10
' Punctuation characters: 0
' Control Characters: 2
'
' The characters in the string "Two
' new
' lines" are:
' 'T' 'w' 'o' '0x000A' 'n' 'e' 'w' '0x000A' 'l' 'i' 'n' 'e' 's'
' Total characters: 13
' Alphanumeric characters: 11
' Punctuation characters: 0
' Control Characters: 2
Hinweise
Tipp
Anstatt die GetEnumerator -Methode aufzurufen, um ein CharEnumerator -Objekt abzurufen, das Sie dann zum Aufzählen einer Zeichenfolge verwenden, sollten Sie stattdessen das Iterationskonstrukt Ihrer Sprache verwenden (in C#, in C++/CLR und in Visual Basic). foreach in C#, for each in C++/CLR und For Each in Visual Basic).
Mit dieser Methode können Sie die einzelnen Zeichen in einer Zeichenfolge iterieren. Beispielsweise rufen die For Each Visual Basic- und foreach C#-Anweisungen diese Methode auf, um ein CharEnumerator -Objekt zurückzugeben, das schreibgeschützten Zugriff auf die Zeichen in dieser Zeichenfolgeninstanz bieten kann.