ArraysArray studies// source https://jsbin.com/dikixab

jsbin.dikixab.js

// -----Arrays----- //

/* Arrays are list-like objects with a large number of mutational and accessible
methods. They can be assigned to variables and are enclosed with squar brackets: */

"use strict";

var exArray = ["I'm element 0", "I'm element 1", "Care to guess?"];

/* As the example demonstrates, arrays are zero-based indexed, and elements can
be accessed by referring to its index: */

console.log(exArray[1]); // logs "I'm element 1"

/* Dot-notation syntax will return an error: */

// console.log(exArray.1); // ERROR, or just won't log anything

/* While technically Javascript considers arrays as objects, it is common to need
to check if an object is an array; the following method will check and return
a boolean value: */

console.log(Array.isArray(exArray)); // true

var notArray = {};
console.log(Array.isArray(notArray)); // false

/* The .length method will return the numeric length of the array's elements: */

console.log(exArray.length); // logs 3

/* Not to be confused with each element's zero-based index, .length begins counting
at 1. The previous example counts three elements and logs "3." This method can
also be used to log the very last element on an array no matter how long it is.*/

console.log(exArray[exArray.length - 1]); // logs "Care to guess?"

/* Altering an element in an array is as simple as using its index number: */

exArray[0] = "I was the third element all along!"
console.log(exArray);