Layman (level 1)

An ordered collection of pieces of information (e.g. words, numbers, names, etc). Each element has a unique number, like in a table. An array is stored in computer memory in a specific way, which allows relatively fast search and retrieval.

Beginner (level 2)

A data structure, a collection of elements each identified by a numerical index. An array is stored in such a way that the position of each element in memory can be computed from its index using a mathematical formula.

Expert (level 3)

A data structure consisting of a group of elements that are accessed by indexing. In most programming languages each element has the same data type and the array occupies a contiguous area of storage. Most programming languages have a built-in array data type.

Some languages seemingly have arrays, but, in the strict sense, do not satisfy its definition. For example, JavaScript arrays are technically objects.


Array in JavaScript

var years = [1950, 1960, 1970, 1980, 1990, 2000, 2010];

Array in C

int main()
   int i;
   int arr[5] = {10,20,30,40,50};

   for (i=0;i<5;i++)
      printf("value of arr[%d] is %d \n", i, arr[i]);


Array in Swift

var words: [String] = ["Oi", "You", "There"]
print("words is of type [String] with \(words.count) items.")


  1. Khan Academy — Intro to Arrays (in JavaScript)
  2. Learning programming: Arrays (in C)


  1. array (Dictionary of Algorithms and Data Structures)
  2. Array data structure (Wikipedia)