how to add elements to an array in c# code example

Example 1: c# add to array

var Freds = new [] { "Fred", "Freddy" };
Freds = Freds.Concat(new [] { "Frederick" }).ToArray();

Example 2: c# how to append in array

List<string> ls = new List<string>();
ls.Add("Hello");

Example 3: c# how to append in array

int[] terms;

for(int runs = 0; runs < 400; runs++)
{
    terms[] = runs;
}