let's Talk about what is an array
In JavaScript, an Array is a data structure to store multiple elements in an ordered way.
Syntax
// square brackets (usual)
let arr = [item1, item2...];
// new Array (Recent Update)
let arr = new Array(item1, item2...);
Array methods
Array Length
Finding the total count of the elements in the array
let fruits = ["Apple", "Orange", "Guava"];
alert( fruits.length );
// 3
Adding elements to Array
Pop() removes the last element of an array and returns it
let fruits = ["Apple", "Orange", "Guava"];
alert( fruits.pop() );
// remove "Guava" and alert it
alert( fruits );
// *Output* : Apple, Orange
Shift() removes the first element of an array and returns it
let fruits = ["Apple", "Orange", "Guava"];
alert( fruits.shift() );
// remove Apple and alert it
alert( fruits );
// *Output* : Orange, Guava
Adding elements to Array
Push() adds a new element to the end of an array
let fruits = ["Apple", "Orange",];
fruits.push("Guava");
// Guava is added at the end
alert( fruits );
// *Output* : Apple, Orange, Guava
Unshift() adds a new element to the beginning of an array
let fruits = ["Orange", "Guava"];
fruits.unshift('Apple');
// Apple is added at the start
alert( fruits );
// *Output* : Apple, Orange, Guava
Splice and Slice
Splice remove/replace elements or adding new elements
let arr = ["Apple", "Orange", "Guava"];
arr.splice(1, 1, "Grapes");
// from index 1 remove 1 element and add Grapes
alert( arr );
// *Output* : Apple, Grapes, Guava
//now arr = ["Apple", "Grapes", "Guava"]
Slice creates a new array, copies elements from index start till the end (not inclusive)
let arr = ["A", "B", "C", "D"];
alert( arr.slice(1, 3) );
// B,C (copy from 1 to 3)
alert( arr.slice(-2) );
// C,D (copy from -2 till the end)
I hope you found this to be helpful. I've categorized it simply so that you can quickly understand the ideas. These are the fundamentals. If you do some exploration, you'll discover more Array Methods.