ArrayList.IndexOf Methode

Definitie

Naamruimte:: System.Collections

Assembly's:: mscorlib.dll, System.Collections.NonGeneric.dll

Assembly's:: netstandard.dll, System.Runtime.dll

Assembly:: System.Collections.NonGeneric.dll

Assembly:: System.Runtime.Extensions.dll

Assembly:: mscorlib.dll

Assembly:: netstandard.dll

Belangrijk

Bepaalde informatie heeft betrekking op een voorlopige productversie die aanzienlijk kan worden gewijzigd voordat deze wordt uitgebracht. Microsoft biedt geen enkele expliciete of impliciete garanties met betrekking tot de informatie die hier wordt verstrekt.

Retourneert de op nul gebaseerde index van het eerste exemplaar van een waarde in of ArrayList in een deel ervan.

Overloads

Name	Description
IndexOf(Object)	Zoekt naar de opgegeven Object en retourneert de op nul gebaseerde index van het eerste exemplaar binnen het hele ArrayListexemplaar.
IndexOf(Object, Int32)	Zoekt naar de opgegeven Object en retourneert de op nul gebaseerde index van het eerste exemplaar binnen het bereik van elementen in de ArrayList opgegeven index tot het laatste element.
IndexOf(Object, Int32, Int32)	Zoekt naar de opgegeven Object en retourneert de op nul gebaseerde index van het eerste exemplaar binnen het bereik van elementen in de ArrayList opgegeven index en bevat het opgegeven aantal elementen.

IndexOf(Object)

Bron:: ArrayList.cs

Bron:: ArrayList.cs

Bron:: ArrayList.cs

Bron:: ArrayList.cs

Bron:: ArrayList.cs

Zoekt naar de opgegeven Object en retourneert de op nul gebaseerde index van het eerste exemplaar binnen het hele ArrayListexemplaar.

public:
 virtual int IndexOf(System::Object ^ value);

public virtual int IndexOf(object value);

public virtual int IndexOf(object? value);

abstract member IndexOf : obj -> int
override this.IndexOf : obj -> int

Public Overridable Function IndexOf (value As Object) As Integer

Parameters

value: Object

De Object te vinden in de ArrayList. De waarde kan zijn null.

Retouren

Int32

De op nul gebaseerde index van het eerste exemplaar van value binnen het hele ArrayList, indien gevonden; anders -1.

Implementeringen

IndexOf(Object)

Voorbeelden

In het volgende codevoorbeeld ziet u hoe u de index kunt bepalen van het eerste exemplaar van een opgegeven element.

using System;
using System.Collections;
public class SamplesArrayList
{

    public static void Main()
    {

        // Creates and initializes a new ArrayList with three elements of the same value.
        ArrayList myAL = new ArrayList();
        myAL.Add( "the" );
        myAL.Add( "quick" );
        myAL.Add( "brown" );
        myAL.Add( "fox" );
        myAL.Add( "jumps" );
        myAL.Add( "over" );
        myAL.Add( "the" );
        myAL.Add( "lazy" );
        myAL.Add( "dog" );
        myAL.Add( "in" );
        myAL.Add( "the" );
        myAL.Add( "barn" );

        // Displays the values of the ArrayList.
        Console.WriteLine( "The ArrayList contains the following values:" );
        PrintIndexAndValues( myAL );

        // Search for the first occurrence of the duplicated value.
        string myString = "the";
        int myIndex = myAL.IndexOf( myString );
        Console.WriteLine( "The first occurrence of \"{0}\" is at index {1}.", myString, myIndex );

        // Search for the first occurrence of the duplicated value in the last section of the ArrayList.
        myIndex = myAL.IndexOf( myString, 4 );
        Console.WriteLine( "The first occurrence of \"{0}\" between index 4 and the end is at index {1}.", myString, myIndex );

        // Search for the first occurrence of the duplicated value in a section of the ArrayList.
        myIndex = myAL.IndexOf( myString, 6, 6 );
        Console.WriteLine( "The first occurrence of \"{0}\" between index 6 and index 11 is at index {1}.", myString, myIndex );

        // Search for the first occurrence of the duplicated value in a small section at the end of the ArrayList.
        myIndex = myAL.IndexOf( myString, 11 );
        Console.WriteLine( "The first occurrence of \"{0}\" between index 11 and the end is at index {1}.", myString, myIndex );
    }

    public static void PrintIndexAndValues(IEnumerable myList)
    {
        int i = 0;
        foreach (Object obj in myList)
            Console.WriteLine("   [{0}]:    {1}", i++, obj);
        Console.WriteLine();
    }
}
/*
This code produces output similar to the following:

The ArrayList contains the following values:
   [0]:    the
   [1]:    quick
   [2]:    brown
   [3]:    fox
   [4]:    jumps
   [5]:    over
   [6]:    the
   [7]:    lazy
   [8]:    dog
   [9]:    in
   [10]:    the
   [11]:    barn

The first occurrence of "the" is at index 0.
The first occurrence of "the" between index 4 and the end is at index 6.
The first occurrence of "the" between index 6 and index 11 is at index 6.
The first occurrence of "the" between index 11 and the end is at index -1.
*/

Imports System.Collections

Public Class SamplesArrayList


    Public Shared Sub Main()

        ' Creates and initializes a new ArrayList with three elements of the same value.
        Dim myAL As New ArrayList()
        myAL.Add("the")
        myAL.Add("quick")
        myAL.Add("brown")
        myAL.Add("fox")
        myAL.Add("jumps")
        myAL.Add("over")
        myAL.Add("the")
        myAL.Add("lazy")
        myAL.Add("dog")
        myAL.Add("in")
        myAL.Add("the")
        myAL.Add("barn")

        ' Displays the values of the ArrayList.
        Console.WriteLine("The ArrayList contains the following values:")
        PrintIndexAndValues(myAL)

        ' Search for the first occurrence of the duplicated value.
        Dim myString As [String] = "the"
        Dim myIndex As Integer = myAL.IndexOf(myString)
        Console.WriteLine("The first occurrence of ""{0}"" is at index {1}.", myString, myIndex)

        ' Search for the first occurrence of the duplicated value in the last section of the ArrayList.
        myIndex = myAL.IndexOf(myString, 4)
        Console.WriteLine("The first occurrence of ""{0}"" between index 4 and the end is at index {1}.", myString, myIndex)

        ' Search for the first occurrence of the duplicated value in a section of the ArrayList.
        myIndex = myAL.IndexOf(myString, 6, 6)
        Console.WriteLine("The first occurrence of ""{0}"" between index 6 and index 11 is at index {1}.", myString, myIndex)

        ' Search for the first occurrence of the duplicated value in a small section at the end of the ArrayList.
        myIndex = myAL.IndexOf(myString, 11)
        Console.WriteLine("The first occurrence of ""{0}"" between index 11 and the end is at index {1}.", myString, myIndex)

    End Sub

    Public Shared Sub PrintIndexAndValues(ByVal myList As IEnumerable)
        Dim i As Integer
        Dim obj As [Object]
        For Each obj In myList
            Console.WriteLine("   [{0}]:    {1}", i, obj)
            i = i + 1
        Next obj
        Console.WriteLine()
    End Sub

End Class

' This code produces the following output.
'
' The ArrayList contains the following values:
' 	[0]:	the
' 	[1]:	quick
' 	[2]:	brown
' 	[3]:	fox
' 	[4]:	jumps
' 	[5]:	over
' 	[6]:	the
' 	[7]:	lazy
' 	[8]:	dog
' 	[9]:	in
' 	[10]:	the
' 	[11]:	barn
' 
' The first occurrence of "the" is at index 0.
' The first occurrence of "the" between index 4 and the end is at index 6.
' The first occurrence of "the" between index 6 and index 11 is at index 6.
' The first occurrence of "the" between index 11 and the end is at index -1.
'

Opmerkingen

De ArrayList zoekopdracht wordt doorgestuurd vanaf het eerste element en eindigt op het laatste element.

Met deze methode wordt een lineaire zoekopdracht uitgevoerd; daarom is deze methode een O(n) bewerking, waarbij n .Count

Deze methode bepaalt gelijkheid door aan te roepen Object.Equals.

Deze methode gebruikt de objecten Equals en CompareTo methoden van de verzameling om item te bepalen of het item bestaat.

Zie ook

Van toepassing op

IndexOf(Object, Int32)

Bron:: ArrayList.cs

Bron:: ArrayList.cs

Bron:: ArrayList.cs

Bron:: ArrayList.cs

Bron:: ArrayList.cs

Zoekt naar de opgegeven Object en retourneert de op nul gebaseerde index van het eerste exemplaar binnen het bereik van elementen in de ArrayList opgegeven index tot het laatste element.

public:
 virtual int IndexOf(System::Object ^ value, int startIndex);

public virtual int IndexOf(object value, int startIndex);

public virtual int IndexOf(object? value, int startIndex);

abstract member IndexOf : obj * int -> int
override this.IndexOf : obj * int -> int

Public Overridable Function IndexOf (value As Object, startIndex As Integer) As Integer

Parameters

value: Object

De Object te vinden in de ArrayList. De waarde kan zijn null.

startIndex: Int32

De op nul gebaseerde startindex van de zoekopdracht. 0 (nul) is geldig in een lege lijst.

Retouren

Int32

De op nul gebaseerde index van het eerste exemplaar van value binnen het bereik van elementen in het ArrayList element dat van startIndex het laatste element is, indien gevonden; anders -1.

Uitzonderingen

ArgumentOutOfRangeException

startIndex valt buiten het bereik van geldige indexen voor de ArrayList.

Voorbeelden

In het volgende codevoorbeeld ziet u hoe u de index kunt bepalen van het eerste exemplaar van een opgegeven element.

using System;
using System.Collections;
public class SamplesArrayList
{

    public static void Main()
    {

        // Creates and initializes a new ArrayList with three elements of the same value.
        ArrayList myAL = new ArrayList();
        myAL.Add( "the" );
        myAL.Add( "quick" );
        myAL.Add( "brown" );
        myAL.Add( "fox" );
        myAL.Add( "jumps" );
        myAL.Add( "over" );
        myAL.Add( "the" );
        myAL.Add( "lazy" );
        myAL.Add( "dog" );
        myAL.Add( "in" );
        myAL.Add( "the" );
        myAL.Add( "barn" );

        // Displays the values of the ArrayList.
        Console.WriteLine( "The ArrayList contains the following values:" );
        PrintIndexAndValues( myAL );

        // Search for the first occurrence of the duplicated value.
        string myString = "the";
        int myIndex = myAL.IndexOf( myString );
        Console.WriteLine( "The first occurrence of \"{0}\" is at index {1}.", myString, myIndex );

        // Search for the first occurrence of the duplicated value in the last section of the ArrayList.
        myIndex = myAL.IndexOf( myString, 4 );
        Console.WriteLine( "The first occurrence of \"{0}\" between index 4 and the end is at index {1}.", myString, myIndex );

        // Search for the first occurrence of the duplicated value in a section of the ArrayList.
        myIndex = myAL.IndexOf( myString, 6, 6 );
        Console.WriteLine( "The first occurrence of \"{0}\" between index 6 and index 11 is at index {1}.", myString, myIndex );

        // Search for the first occurrence of the duplicated value in a small section at the end of the ArrayList.
        myIndex = myAL.IndexOf( myString, 11 );
        Console.WriteLine( "The first occurrence of \"{0}\" between index 11 and the end is at index {1}.", myString, myIndex );
    }

    public static void PrintIndexAndValues(IEnumerable myList)
    {
        int i = 0;
        foreach (Object obj in myList)
            Console.WriteLine("   [{0}]:    {1}", i++, obj);
        Console.WriteLine();
    }
}
/*
This code produces output similar to the following:

The ArrayList contains the following values:
   [0]:    the
   [1]:    quick
   [2]:    brown
   [3]:    fox
   [4]:    jumps
   [5]:    over
   [6]:    the
   [7]:    lazy
   [8]:    dog
   [9]:    in
   [10]:    the
   [11]:    barn

The first occurrence of "the" is at index 0.
The first occurrence of "the" between index 4 and the end is at index 6.
The first occurrence of "the" between index 6 and index 11 is at index 6.
The first occurrence of "the" between index 11 and the end is at index -1.
*/

Imports System.Collections

Public Class SamplesArrayList


    Public Shared Sub Main()

        ' Creates and initializes a new ArrayList with three elements of the same value.
        Dim myAL As New ArrayList()
        myAL.Add("the")
        myAL.Add("quick")
        myAL.Add("brown")
        myAL.Add("fox")
        myAL.Add("jumps")
        myAL.Add("over")
        myAL.Add("the")
        myAL.Add("lazy")
        myAL.Add("dog")
        myAL.Add("in")
        myAL.Add("the")
        myAL.Add("barn")

        ' Displays the values of the ArrayList.
        Console.WriteLine("The ArrayList contains the following values:")
        PrintIndexAndValues(myAL)

        ' Search for the first occurrence of the duplicated value.
        Dim myString As [String] = "the"
        Dim myIndex As Integer = myAL.IndexOf(myString)
        Console.WriteLine("The first occurrence of ""{0}"" is at index {1}.", myString, myIndex)

        ' Search for the first occurrence of the duplicated value in the last section of the ArrayList.
        myIndex = myAL.IndexOf(myString, 4)
        Console.WriteLine("The first occurrence of ""{0}"" between index 4 and the end is at index {1}.", myString, myIndex)

        ' Search for the first occurrence of the duplicated value in a section of the ArrayList.
        myIndex = myAL.IndexOf(myString, 6, 6)
        Console.WriteLine("The first occurrence of ""{0}"" between index 6 and index 11 is at index {1}.", myString, myIndex)

        ' Search for the first occurrence of the duplicated value in a small section at the end of the ArrayList.
        myIndex = myAL.IndexOf(myString, 11)
        Console.WriteLine("The first occurrence of ""{0}"" between index 11 and the end is at index {1}.", myString, myIndex)

    End Sub

    Public Shared Sub PrintIndexAndValues(ByVal myList As IEnumerable)
        Dim i As Integer
        Dim obj As [Object]
        For Each obj In myList
            Console.WriteLine("   [{0}]:    {1}", i, obj)
            i = i + 1
        Next obj
        Console.WriteLine()
    End Sub

End Class

' This code produces the following output.
'
' The ArrayList contains the following values:
' 	[0]:	the
' 	[1]:	quick
' 	[2]:	brown
' 	[3]:	fox
' 	[4]:	jumps
' 	[5]:	over
' 	[6]:	the
' 	[7]:	lazy
' 	[8]:	dog
' 	[9]:	in
' 	[10]:	the
' 	[11]:	barn
' 
' The first occurrence of "the" is at index 0.
' The first occurrence of "the" between index 4 and the end is at index 6.
' The first occurrence of "the" between index 6 and index 11 is at index 6.
' The first occurrence of "the" between index 11 and the end is at index -1.
'

Opmerkingen

De ArrayList zoekopdracht begint bij startIndex en eindigt op het laatste element.

Met deze methode wordt een lineaire zoekopdracht uitgevoerd; daarom is deze methode een O(n) bewerking, waarbij n het aantal elementen van startIndex tot het einde van de ArrayList.

Deze methode bepaalt gelijkheid door aan te roepen Object.Equals.

Deze methode gebruikt de objecten Equals en CompareTo methoden van de verzameling om item te bepalen of het item bestaat.

Zie ook

Van toepassing op

IndexOf(Object, Int32, Int32)

Bron:: ArrayList.cs

Bron:: ArrayList.cs

Bron:: ArrayList.cs

Bron:: ArrayList.cs

Bron:: ArrayList.cs

Zoekt naar de opgegeven Object en retourneert de op nul gebaseerde index van het eerste exemplaar binnen het bereik van elementen in de ArrayList opgegeven index en bevat het opgegeven aantal elementen.

public:
 virtual int IndexOf(System::Object ^ value, int startIndex, int count);

public virtual int IndexOf(object value, int startIndex, int count);

public virtual int IndexOf(object? value, int startIndex, int count);

abstract member IndexOf : obj * int * int -> int
override this.IndexOf : obj * int * int -> int

Public Overridable Function IndexOf (value As Object, startIndex As Integer, count As Integer) As Integer

Parameters

value: Object

De Object te vinden in de ArrayList. De waarde kan zijn null.

startIndex: Int32

De op nul gebaseerde startindex van de zoekopdracht. 0 (nul) is geldig in een lege lijst.

count: Int32

Het aantal elementen in de sectie dat moet worden gezocht.

Retouren

Int32

De op nul gebaseerde index van het eerste exemplaar binnen value het bereik van elementen in de ArrayList elementen die beginnen bij startIndex en bevat count het aantal elementen, indien gevonden; anders -1.

Uitzonderingen

ArgumentOutOfRangeException

startIndex valt buiten het bereik van geldige indexen voor de ArrayList.

– of –

count is kleiner dan nul.

– of –

startIndex en count geef geen geldige sectie op in de ArrayList.

Voorbeelden

In het volgende codevoorbeeld ziet u hoe u de index kunt bepalen van het eerste exemplaar van een opgegeven element.

using System;
using System.Collections;
public class SamplesArrayList
{

    public static void Main()
    {

        // Creates and initializes a new ArrayList with three elements of the same value.
        ArrayList myAL = new ArrayList();
        myAL.Add( "the" );
        myAL.Add( "quick" );
        myAL.Add( "brown" );
        myAL.Add( "fox" );
        myAL.Add( "jumps" );
        myAL.Add( "over" );
        myAL.Add( "the" );
        myAL.Add( "lazy" );
        myAL.Add( "dog" );
        myAL.Add( "in" );
        myAL.Add( "the" );
        myAL.Add( "barn" );

        // Displays the values of the ArrayList.
        Console.WriteLine( "The ArrayList contains the following values:" );
        PrintIndexAndValues( myAL );

        // Search for the first occurrence of the duplicated value.
        string myString = "the";
        int myIndex = myAL.IndexOf( myString );
        Console.WriteLine( "The first occurrence of \"{0}\" is at index {1}.", myString, myIndex );

        // Search for the first occurrence of the duplicated value in the last section of the ArrayList.
        myIndex = myAL.IndexOf( myString, 4 );
        Console.WriteLine( "The first occurrence of \"{0}\" between index 4 and the end is at index {1}.", myString, myIndex );

        // Search for the first occurrence of the duplicated value in a section of the ArrayList.
        myIndex = myAL.IndexOf( myString, 6, 6 );
        Console.WriteLine( "The first occurrence of \"{0}\" between index 6 and index 11 is at index {1}.", myString, myIndex );

        // Search for the first occurrence of the duplicated value in a small section at the end of the ArrayList.
        myIndex = myAL.IndexOf( myString, 11 );
        Console.WriteLine( "The first occurrence of \"{0}\" between index 11 and the end is at index {1}.", myString, myIndex );
    }

    public static void PrintIndexAndValues(IEnumerable myList)
    {
        int i = 0;
        foreach (Object obj in myList)
            Console.WriteLine("   [{0}]:    {1}", i++, obj);
        Console.WriteLine();
    }
}
/*
This code produces output similar to the following:

The ArrayList contains the following values:
   [0]:    the
   [1]:    quick
   [2]:    brown
   [3]:    fox
   [4]:    jumps
   [5]:    over
   [6]:    the
   [7]:    lazy
   [8]:    dog
   [9]:    in
   [10]:    the
   [11]:    barn

The first occurrence of "the" is at index 0.
The first occurrence of "the" between index 4 and the end is at index 6.
The first occurrence of "the" between index 6 and index 11 is at index 6.
The first occurrence of "the" between index 11 and the end is at index -1.
*/

Imports System.Collections

Public Class SamplesArrayList


    Public Shared Sub Main()

        ' Creates and initializes a new ArrayList with three elements of the same value.
        Dim myAL As New ArrayList()
        myAL.Add("the")
        myAL.Add("quick")
        myAL.Add("brown")
        myAL.Add("fox")
        myAL.Add("jumps")
        myAL.Add("over")
        myAL.Add("the")
        myAL.Add("lazy")
        myAL.Add("dog")
        myAL.Add("in")
        myAL.Add("the")
        myAL.Add("barn")

        ' Displays the values of the ArrayList.
        Console.WriteLine("The ArrayList contains the following values:")
        PrintIndexAndValues(myAL)

        ' Search for the first occurrence of the duplicated value.
        Dim myString As [String] = "the"
        Dim myIndex As Integer = myAL.IndexOf(myString)
        Console.WriteLine("The first occurrence of ""{0}"" is at index {1}.", myString, myIndex)

        ' Search for the first occurrence of the duplicated value in the last section of the ArrayList.
        myIndex = myAL.IndexOf(myString, 4)
        Console.WriteLine("The first occurrence of ""{0}"" between index 4 and the end is at index {1}.", myString, myIndex)

        ' Search for the first occurrence of the duplicated value in a section of the ArrayList.
        myIndex = myAL.IndexOf(myString, 6, 6)
        Console.WriteLine("The first occurrence of ""{0}"" between index 6 and index 11 is at index {1}.", myString, myIndex)

        ' Search for the first occurrence of the duplicated value in a small section at the end of the ArrayList.
        myIndex = myAL.IndexOf(myString, 11)
        Console.WriteLine("The first occurrence of ""{0}"" between index 11 and the end is at index {1}.", myString, myIndex)

    End Sub

    Public Shared Sub PrintIndexAndValues(ByVal myList As IEnumerable)
        Dim i As Integer
        Dim obj As [Object]
        For Each obj In myList
            Console.WriteLine("   [{0}]:    {1}", i, obj)
            i = i + 1
        Next obj
        Console.WriteLine()
    End Sub

End Class

' This code produces the following output.
'
' The ArrayList contains the following values:
' 	[0]:	the
' 	[1]:	quick
' 	[2]:	brown
' 	[3]:	fox
' 	[4]:	jumps
' 	[5]:	over
' 	[6]:	the
' 	[7]:	lazy
' 	[8]:	dog
' 	[9]:	in
' 	[10]:	the
' 	[11]:	barn
' 
' The first occurrence of "the" is at index 0.
' The first occurrence of "the" between index 4 and the end is at index 6.
' The first occurrence of "the" between index 6 and index 11 is at index 6.
' The first occurrence of "the" between index 11 and the end is at index -1.
'

Opmerkingen

De ArrayList zoekopdracht begint bij startIndex en eindigt op startIndex plus count min 1, als count deze groter is dan 0.

Met deze methode wordt een lineaire zoekopdracht uitgevoerd; daarom is deze methode een O(n) bewerking, waarbij n .count

Deze methode bepaalt gelijkheid door aan te roepen Object.Equals.

Deze methode gebruikt de objecten Equals en CompareTo methoden van de verzameling om item te bepalen of het item bestaat.

Zie ook

Van toepassing op

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