Create and read an array

The idea

An array stores a fixed number of elements of one type. int[] scores = { 3, 5 }; creates two integer elements. The square brackets in int[] describe the type, while scores[0] reads the first stored value. Length reports the number of elements, so the final valid position is Length - 1.

An array element can change without changing the array length. scores[1] = 8; replaces the second number. An int array cannot directly store a string. Reading or writing beyond the valid indexes throws an IndexOutOfRangeException; make sure an array is nonempty before using index zero or its last index.

Begin with one array and explicit positions. The next control-flow chapter shows how foreach can visit every value. The later value/reference chapter explains what happens when two variables refer to the same array; you do not need aliasing or cloning to make and read this first array.

using System;
int[] scores = { 3, 5 };
scores[1] = 8;
Console.WriteLine(scores[0]);
Console.WriteLine(scores[scores.Length - 1]);
Console.WriteLine(scores.Length);

3
8
2

Only the second element changes. The array still has two elements, at positions zero and one.