csharp list code example

Example 1: c# lists

// ------------------- How to initialize Lists? --------------------- //

using System.Collections.Generic   // You need to include this!

// 1º Method
var myList = new List<int>();
//OR
List<int> myList = new List<int>();
  

// 2º Method
List<int> myList = new List<int>() {2, 5, 9, 12};


// 3º Method
string myString = "Hello"
List<char> myList = new List<char>(myString);  // Creates a list of characters from that string 
//OR
var myFirstList = new List<int>() {9, 2, 4, 3, 2, 1};
var mySecondList = new List<int>(myFirstList);   // Copy a list to a second list 




// -------- How to dynamically change the List of elements? --------- //

// Use the Add or Insert method to add one element
myList.Add(4);  

myList.Insert(0,3)  // Insert element "3" in position "0"
  

// Use the AddRange method to add many elements (you can use an array or
// list, for passing the values)
myList.AddRange(new int[3] {3, 5, 5, 9, 2}); 


// Use the Remove method to eliminate specific elements
for (int i = 0; i < myList.Count; i++)   // Use a for loop to remove 
{										// repeated elements
  if ( myList[i] == 5)
  {
  	myList.Remove(myList[i]);
    i--;
  }
}

// Use the Clear method to remove all elements from the list
myList.Clear();




// ---------------- How to create a List of Lists? ------------------ //

List<List<int>> myList = new List<List<int>>(){
	new List<int>() {1,2,3},
	new List<int>() {4,5,6},
	new List<int>() {7,8,9}
};
		
Console.WriteLine(myList.ElementAt(0).ElementAt(1)); // You get "2"

Example 2: csharp list

List<int> numbers = new List<int>() { 1, 2, 5, 7, 8, 10 };
Console.WriteLine(numbers[0]); // prints 1
Console.WriteLine(numbers[1]); // prints 2
Console.WriteLine(numbers[2]); // prints 5
Console.WriteLine(numbers[3]); // prints 7

// using foreach LINQ method
numbers.ForEach(num => Console.WriteLine(num + ", "));//prints 1, 2, 5, 7, 8, 10,

// using for loop
for(int i = 0; i < numbers.Count; i++)
    Console.WriteLine(numbers[i]);