List

The followoing code is the structure of List class.

 
public class List <T> : IList <T>
{
    public List ();
    public List (IEnumerable<T> collection);
    public List (int capacity);
    
    // Add+Insert
    public void Add (T item);
    public void AddRange  (IEnumerable<T> collection);
    public void Insert  (int index, T item);
    public void InsertRange (int index, IEnumerable<T> collection);
    
    // Remove
    public bool Remove  (T item);
    public void RemoveAt  (int index);
    public void RemoveRange (int index, int count);
    public int  RemoveAll (Predicate<T> match);
    
    // Indexing
    public T this [int index] { get; set; }
    public List<T> GetRange (int index, int count);
    public Enumerator<T> GetEnumerator();
    
    // Exporting, copying and converting:
    public T[] ToArray();
    public void CopyTo (T[] array);
    public void CopyTo (T[] array, int arrayIndex);
    public void CopyTo (int index, T[] array, int arrayIndex, int count);
     
    public ReadOnlyCollection<T> AsReadOnly();
    public List<TOutput> ConvertAll<TOutput> (Converter <T,TOutput> converter);
    // Other:
    public void Reverse();  
    public int Capacity { get;set; }  
    public void TrimExcess();  
    public void Clear();  
}
  

The following code shows how to add elements a List.

 
using System;
using System.Collections;
using System.Collections.Generic;

class Sample
{
    public static void Main()
    {
        //Create a List of Strings
        //String-typed list
        List<string> words = new List<string>();  

        words.Add("A");
        words.Add("B");
        words.AddRange(new[] { "C", "D" });
        words.Insert(0, "A"); // Insert at start 
        words.InsertRange(0, new[] { "E", "F" });
        

    }

}
  

Remove elements from a List

 
using System;
using System.Collections;
using System.Collections.Generic;

class Sample
{
    public static void Main()
    {
        //Create a List of Strings
        //String-typed list
        List<string> words = new List<string>();  

        words.Add("A");
        words.Add("B");
        words.Add("C");
        words.Add("D");
        words.Add("E");
        words.Add("F");

        words.Remove("A");
        words.RemoveAt(3);  // Remove the 4th element 
        words.RemoveRange (0, 2); // Remove first 2 elements

        // Remove all strings starting in 'n':
        words.RemoveAll(s => s.StartsWith("n"));


    }
}
  

Get elements from List

 
using System;
using System.Collections;
using System.Collections.Generic;

class Sample
{
    public static void Main()
    {
        //Create a List of Strings
        //String-typed list
        List<string> words = new List<string>();  

        words.Add("A");
        words.Add("B");
        words.Add("C");
        words.Add("D");
        words.Add("E");
        words.Add("F");


        Console.WriteLine("First:"+words[0]);  // first word 
        Console.WriteLine ("Last:"+words[words.Count - 1]);  // last word 

        foreach (string s in words) 
            Console.WriteLine ("all:"+s);   // all words 

        IList<string> subset = words.GetRange (1, 2); // 2nd->3rd words
   }
}
  

The output:


First:A
Last:F
all:A
all:B
all:C
all:D
all:E
all:F

Convert List to an Array

 
using System;
using System.Collections;
using System.Collections.Generic;

class Sample
{
    public static void Main()
    {
        //Create a List of Strings
        //String-typed list
        List<string> words = new List<string>();  

        words.Add("A");
        words.Add("B");
        words.Add("C");
        words.Add("D");
        words.Add("E");
        words.Add("F");


        string[] wordsArray = words.ToArray();  // Creates a new typed array

        // Copy first two elements to the end of an existing array:
        string[] existing = new string[1000];
        words.CopyTo(0, existing, 998, 2);
   }
}

Convert List element

 
using System;
using System.Collections;
using System.Collections.Generic;

class Sample
{
    public static void Main()
    {
        //Create a List of Strings
        //String-typed list
        List<string> words = new List<string>();  

        words.Add("A");
        words.Add("B");
        words.Add("C");
        words.Add("D");
        words.Add("E");
        words.Add("F");

        List<string> upperCastWords = words.ConvertAll(s => s.ToUpper()); 
        List<int> lengths = words.ConvertAll(s => s.Length);
   }
}
  
java2s.com  |  | Contact Us | Privacy Policy
Copyright 2009 - 12 Demo Source and Support. All rights reserved.
All other trademarks are property of their respective owners.