Mastering JavaScript Arrays: Techniques and Best Practices

JavaScript Arrays

Introduction to JavaScript arrays

In JavaScript, an array is an ordered list of values. Each value is called an element specified by an index:

In JavaScript, an array is an ordered list of values. Each value is called an element specified by an index:

let car1 = "Saab";
let car2 = "Volvo";
let car3 ="BMW";

Declaration
There are two syntaxes for creating an empty array:

let arr = new Array();
let arr = [];

`let fruits = ["Apple", "Orange", "Plum"];

alert( fruits[0] ); // Apple
alert( fruits[1] ); // Orange
alert( fruits[2] ); // Plum`

In JavaScript, arrays aren't primitives but are instead Array objects with the following core characteristics:

JavaScript arrays are resizable and can contain a mix of different data types. (When those characteristics are undesirable, use typed arrays instead.)

JavaScript arrays are not associative arrays, and so, array elements cannot be accessed using arbitrary strings as indexes, but must be accessed using nonnegative integers (or their respective string form) as indexes.

JavaScript arrays are zero-indexed: the first element of an array is at index 0, the second is at index 1, and so on, and the last element is at the value of the array's length property minus 1.

JavaScript array-copy operations create shallow copies. (All standard built-in copy operations with any JavaScript objects create shallow copies, rather than deep copies.