ArrayList Search

In this chapter you will learn:

How to search an ArrayList
How to search from the end of an ArrayList
How to search within a range of an ArrayList

Search for index

The following code searches for the first occurrence of the duplicated value.

using System;//from j a  v  a 2  s  . c om
using System.Collections;
public class SamplesArrayList
{

    public static void Main()  
    {
        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" );
        String myString = "the";
        int myIndex = myAL.IndexOf( myString );
        Console.WriteLine( "The first occurrence of \"{0}\" 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);
    }
}

Search from the end

Search for the first occurrence of the duplicated value in the last section of the ArrayList.

using System;/* j  av  a2  s. c om*/
using System.Collections;
public class SamplesArrayList
{

    public static void Main()  
    {
        ArrayList myAL = new ArrayList();
        myAL.Add( "the" );
        myAL.Add( "quick" );
        myAL.Add( "brown" );
        myAL.Add( "fox" );
        myAL.Add( "the" );
  
        String myString = "the";
        int myIndex = -1;

        myIndex = myAL.IndexOf( myString, 4 );
        Console.WriteLine(myIndex );
    }

    public static void PrintIndexAndValues(IEnumerable myList)
    {
        int i = 0;
        foreach (Object obj in myList)
            Console.WriteLine("   [{0}]:    {1}", i++, obj);
    }
}

Search inside a range

The following code shows how to search for the first occurrence of the duplicated value in a section of the ArrayList.

using System;//ja v a2 s. c o m
using System.Collections;
public class SamplesArrayList
{

    public static void Main()  
    {
        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" );

        String myString = "the";
        int myIndex = -1;

        myIndex = myAL.IndexOf( myString, 6, 6 );
        Console.WriteLine( myIndex );
    }
    public static void PrintIndexAndValues(IEnumerable myList)
    {
        int i = 0;
        foreach (Object obj in myList)
            Console.WriteLine("   [{0}]:    {1}", i++, obj);
    }
}

Next chapter...

What you will learn in the next chapter: