2 min to read
What are arrays?
Arrays are collections of data.
Before you read this article, we recommend that you read the What is a variable, What are loops and What are data-types articles.
In the What are loops article, we introduced the concept of having a “list” of people.
recipients = James, John, Jimmy, Jane, Jake, Jemma, Joanne, Juliet, Jessica, Josh
In most languages, this “list” would have been created using an array. An array is simply a collection of data.
An array is made up of elements. An element is an item within an array. In the above example, there are 10 elements (
James is the first element,
John is the second etc).
Syntactically an array is usually denoted using square brackets (
]) with a comma separating each element. Arrays can hold any data-type.
Our list of recipients shows a list of names, which are Strings. To convert this list into an Array we would need to use quotation marks (
") so they are interpreted as such.
recipients = ["James", "John", "Jimmy", "Jane", "Jake", "Jemma", "Joanne", "Juliet", "Jessica", "Josh"]
It’s just as easy to create an Array with other data-types.
integers = [1,6,3,5,98] floats = [2.4, 56.1, 46.1] booleans = [true, true, false, true, false] mixed = [5, true, 2.4, false, 3, 64.2]
Array elements have a corresponding number (index). This number is used to target specific elements. In most programming languages indexing starts at zero. Using our recipients example, this would look like the following:
recipients = ["James", "John", "Jimmy", "Jane", ... ] index | 0 | 1 | 2 | 3 | ...
As mentioned above, you can use the index to target specific elements in any order you want:
array // => Jimmy array // => James array // => Jane