ArrayList.IndexOf Metódus

Definíció

Egy érték első előfordulásának nullaalapú indexét adja vissza a ArrayList benne vagy egy részben.

Túlterhelések

Name Description
IndexOf(Object)

Megkeresi a megadott Object értéket, és a teljes első ArrayListelőfordulás nulla alapú indexét adja vissza.

IndexOf(Object, Int32)

Megkeresi a megadott Object értéket, és az első előfordulás nulla alapú indexét adja vissza a megadott indextől az utolsó elemig terjedő elemek tartományán ArrayList belül.

IndexOf(Object, Int32, Int32)

Megkeresi a megadott Object értéket, és visszaadja az első előfordulás nullaalapú indexét a megadott indexnél kezdődő elemek ArrayList tartományán belül, és a megadott számú elemet tartalmazza.

IndexOf(Object)

Forrás:
ArrayList.cs
Forrás:
ArrayList.cs
Forrás:
ArrayList.cs
Forrás:
ArrayList.cs
Forrás:
ArrayList.cs

Megkeresi a megadott Object értéket, és a teljes első ArrayListelőfordulás nulla alapú indexét adja vissza.

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

Paraméterek

value
Object

A Object keresendő ArrayList. Az érték lehet null.

Válaszok

Az egész valueelső előfordulásának nulla alapú indexe ArrayList , ha található; ellenkező esetben -1.

Megvalósítás

Példák

Az alábbi példakód bemutatja, hogyan határozható meg egy adott elem első előfordulásának indexe.

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.
'

Megjegyzések

A ArrayList rendszer az első elemtől kezdve az utolsó elemig előre keres.

Ez a módszer lineáris keresést végez; ezért ez a módszer egy O(n) művelet, ahol n van Count.

Ez a metódus hívással határozza meg az egyenlőséget Object.Equals.

Ez a metódus a gyűjtemény objektumait és Equals metódusait CompareToitem használja annak meghatározására, hogy létezik-e elem.

Lásd még

A következőre érvényes:

IndexOf(Object, Int32)

Forrás:
ArrayList.cs
Forrás:
ArrayList.cs
Forrás:
ArrayList.cs
Forrás:
ArrayList.cs
Forrás:
ArrayList.cs

Megkeresi a megadott Object értéket, és az első előfordulás nulla alapú indexét adja vissza a megadott indextől az utolsó elemig terjedő elemek tartományán ArrayList belül.

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

Paraméterek

value
Object

A Object keresendő ArrayList. Az érték lehet null.

startIndex
Int32

A keresés nulla alapú kezdőindexe. A 0 (nulla) üres listában érvényes.

Válaszok

Az elemek tartományán belüli első előfordulás nullaalapú indexe value , ha megtalálható, akkor az ArrayList utolsó elemig startIndex terjed, ellenkező esetben -1.

Kivételek

startIndexkívül esik az érvényes indexek tartományán.ArrayList

Példák

Az alábbi példakód bemutatja, hogyan határozható meg egy adott elem első előfordulásának indexe.

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.
'

Megjegyzések

A ArrayList rendszer az utolsó elemtől startIndex kezdődően és az utolsó elemig előre keres.

Ez a módszer lineáris keresést végez; ezért ez a módszer egy O(n) művelet, ahol n az elemek száma a végétől startIndex a végéig ArrayList.

Ez a metódus hívással határozza meg az egyenlőséget Object.Equals.

Ez a metódus a gyűjtemény objektumait és Equals metódusait CompareToitem használja annak meghatározására, hogy létezik-e elem.

Lásd még

A következőre érvényes:

IndexOf(Object, Int32, Int32)

Forrás:
ArrayList.cs
Forrás:
ArrayList.cs
Forrás:
ArrayList.cs
Forrás:
ArrayList.cs
Forrás:
ArrayList.cs

Megkeresi a megadott Object értéket, és visszaadja az első előfordulás nullaalapú indexét a megadott indexnél kezdődő elemek ArrayList tartományán belül, és a megadott számú elemet tartalmazza.

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

Paraméterek

value
Object

A Object keresendő ArrayList. Az érték lehet null.

startIndex
Int32

A keresés nulla alapú kezdőindexe. A 0 (nulla) üres listában érvényes.

count
Int32

A keresendő szakasz elemeinek száma.

Válaszok

Az elemek tartományán belüli első előfordulás nulla alapú indexevalue, amely a kezdő ArrayList és startIndex az elemek számát tartalmazzacount, ha található; ellenkező esetben -1.

Kivételek

startIndexkívül esik az érvényes indexek tartományán.ArrayList

-vagy-

count kisebb, mint nulla.

-vagy-

startIndex és count ne adjon meg érvényes szakaszt a ArrayList.

Példák

Az alábbi példakód bemutatja, hogyan határozható meg egy adott elem első előfordulásának indexe.

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.
'

Megjegyzések

A ArrayList program a 0-nál nagyobb mínusz 1-nél startIndex kezdődik startIndex és végződik countcount.

Ez a módszer lineáris keresést végez; ezért ez a módszer egy O(n) művelet, ahol n van count.

Ez a metódus hívással határozza meg az egyenlőséget Object.Equals.

Ez a metódus a gyűjtemény objektumait és Equals metódusait CompareToitem használja annak meghatározására, hogy létezik-e elem.

Lásd még

A következőre érvényes: