C# | Get or set the element at the specified index in ArrayList
ArrayList.Item[Int32] Property is used to get or set the element at the specified index in ArrayList. Syntax:
public virtual object this[int index] { get; set; }
Here, index is the zero-based index of the element to get or set. Return Value: It returns the element of Object type at the specified index. Exception: This property will throw ArgumentOutOfRangeException if the index is less than zero or is equal to or greater than Count. Below programs illustrate the use of above-discussed property: Example 1:
CSharp
// C# code to get or set the element at // the specified index in ArrayList using System; using System.Collections; class GFG { // Driver code public static void Main() { // Creating an ArrayList ArrayList myList = new ArrayList(); // Adding elements to ArrayList myList.Add( "A" ); myList.Add( "B" ); myList.Add( "C" ); myList.Add( "D" ); myList.Add( "E" ); myList.Add( "F" ); // Displaying the elements // in the ArrayList foreach ( string str in myList) { Console.WriteLine(str); } Console.WriteLine( "After Item[int32] Property: " ); // setting the value at index 2 myList[2] = "Z" ; // Displaying the elements // in the ArrayList foreach ( string str in myList) { Console.WriteLine(str); } } } |
A B C D E F After Item[int32] Property: A B Z D E F
Example 2:
CSharp
// C# code to get or set the element at // the specified index in ArrayList using System; using System.Collections; using System.Collections.Generic; class GFG { // Driver code public static void Main() { // Creating an ArrayList ArrayList myList = new ArrayList(); // Adding elements to ArrayList // Adding elements to ArrayList myList.Add(2); myList.Add(4); myList.Add(6); myList.Add(8); myList.Add(10); myList.Add(12); myList.Add(14); myList.Add(16); myList.Add(18); myList.Add(20); // Displaying the elements // in the ArrayList foreach ( int i in myList) { Console.WriteLine(i); } Console.WriteLine( "After Item[int32] Property: " ); // setting the value at index 8 // this will give error as index // is greater than count myList[10] = 56; // Displaying the elements // in the ArrayList foreach ( int j in myList) { Console.WriteLine(j); } } } |
Runtime Error:
Unhandled Exception: System.ArgumentOutOfRangeException: Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index
Time complexity: O(n) for traversing ArrayList
Auxiliary Space: O(n) where n is the size of the ArrayList
Reference:
- https://docs.microsoft.com/en-us/dotnet/api/system.collections.arraylist.item?view=netframework-4.7.2
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