Arrays are list-like objects whose prototype has methods to perform traversal and mutation operations. Neither the length of a JavaScript array nor the types of its elements are fixed. Since an array’s length can change at any time, and data can be stored at non-contiguous locations in the array, JavaScript arrays are not guaranteed to be dense; this depends on how the programmer chooses to use them.
Example of JavaScript Array
Create an Array
let fruits = ['Apple', 'Banana'] console.log(fruits.length) // 2
Access an Array item using the index position
let first = fruits[0] // Apple let last = fruits[fruits.length - 1] // Banana
Difference Between “{}” and “[]” while Declaring A JavaScript Array?
[] is declaring an array.
{} is declaring an object.
An array has all the features of an object with additional features (you can think of an array like a sub-class of an object) where additional methods and capabilities are added in the Array sub-class. In fact, typeof [] === "object" to further show you that an array is an object.
The additional features consist of a magic .length property that keeps track of the number of items in the array and a whole slew of methods for operating on the array such as .push(), .pop(), .slice(), .splice(), etc… You can see a list of array methods here.
An object gives you the ability to associate a property name with a value as in: