Page 96 - CSharp/C#

// output:
// one
// two

// exchange the element on the first position
// note that all collections start with the index 0
myArray[0] = "something else";

// enumerate through the array again
foreach(var item in myArray)
{
Console.WriteLine(item);
}

// output:
// something else
// two

List

List<T> is a list of a given type. Items can be added, inserted, removed and addressed by index.

using System.Collections.Generic;

var list = new List<int>() { 1, 2, 3, 4, 5 };
list.Add(6);
Console.WriteLine(list.Count); // 6
list.RemoveAt(3);
Console.WriteLine(list.Count); // 5
Console.WriteLine(list[3]); // 5

List<T> can be thought of as an array that you can resize. Enumerating over the collection in order
is quick, as is access to individual elements via their index. To access elements based on some
aspect of their value, or some other key, a Dictionary<T> will provide faster lookup.

Dictionary

Dictionary<TKey, TValue> is a map. For a given key there can be one value in the dictionary.

using System.Collections.Generic;

var people = new Dictionary<string, int>
{
{ "John", 30 }, {"Mary", 35}, {"Jack", 40}
};

// Reading data
Console.WriteLine(people["John"]); // 30
Console.WriteLine(people["George"]); // throws KeyNotFoundException

int age;
if (people.TryGetValue("Mary", out age))
{
Console.WriteLine(age); // 35
}

https://riptutorial.com/ 42