Toby Rogers

Toby Rogers

1562400677

All About JavaScript Arrays Methods

Web development or web programming gave birth to dynamic web applications. With the rise of the web, JavaScript has become one of the most important languages in today’s world. This JavaScript Array article will take you to the depths of array methods in JavaScript in the following sequence:

  • Introduction to JavaScript
  • Fundamentals of JavaScript
  • JavaScript Array
  • Difference between Array and Objects
  • JavaScript Array Methods

Introduction to JavaScript

JavaScript is a high level, interpreted, programming language used to make web pages more interactive. It is a very powerful client-side scripting language which makes your webpage more lively and interactive.

It is a programming language that helps you to implement a complex and beautiful design on web pages. If you want your web page to look alive and do a lot more than just gawk at you, JavaScript is a must.

Fundamentals of JavaScript

If you are new to the language, you need to know some of the fundamentals of JavaScript that will help you start writing your code. The basics include:

JavaScript Array

An array is a data structure that contains a list of elements which store multiple values under a single variable.

To declare an array in JavaScript use the ‘let’ keyword with square brackets and enclose all the elements within them. The syntax is as follows:

let ListItems=[];
ListItems=['shoes','watch','bag'];

You can also declare it as:

let ListItems=['shoes','watch','bag'];

Difference between Array and Objects

JavaScript variables can be objects. Arrays are considered to be special kinds of objects. Because of this, you can have variables of different types in the same Array.

myArray[0] = Date.now;
myArray[1] = myFunction;
myArray[2] = myItems;

In JavaScript, arrays use numbered indexes. Whereas, objects are used as named indexes.

JavaScript Array Methods

The purpose of using an array is to store** multiple values** in a single entity of a declared variable. Arrays are used when we want to access elements in an orderly fashion using a single variable. One can store strings, boolean and numbers in a single array.

There are different JavaScript array methods in order to perform various tasks such as:
push() – It is easy to remove elements and add new elements while working with arrays. The push() method adds a new element to the end of an array. The return value is the new array length.
Example:

let listItems = ['bag','shoes','dress'];
console.log(listItems.push('watch'));

Output:

4

Push() doest not return the value that has been added to the array. It only returns the new length of the array.
**pop() – **The pop() method is used to remove the last element from an array. It returns the value that has been popped out.
Example:

let listItems = ['bag','shoes','dress'];
console.log(listItems.pop());

Output:

dress

Pop() returns the value that has been removed and not the array length like Push().
shift() – Shifting is similar to popping, working on the first element instead of the last. The shift() method is used to remove the first array element and shifts all other elements to a lower index. It will return you the string that has been shifted out.
Example:

let listItems = ['bag','shoes','dress'];
console.log(listItems.shift());

Output:

bag

Shift() works same as pop() but it returns the first element of the array instead of the last one.
unshift() – The unshift() method adds a new element at the beginning of an array and unshifts older elements. It is similar to Push() and returns the new array length.
**Example: **

let listItems = ['bag','shoes','dress','watch'];
console.log(listItems.unshift('phone'));

Output:

5

Unshift() will add the new element into the array and return the length of the new array.
concat() – The concat() method creates a new array by concatenating or merging existing arrays. It does not modify the existing array and always returns a new array.
Example:

let arr1 = ['red','blue','green'];
let arr2 = ['colors','spraypaint', 'brush'];
let newArr = arr1.concat(arr2);
console.log(newArr);

Output:


toString() – The toString() method is used to convert an array to a string of array values, separated by commas.
Example:

let colors = ['red','blue','green'];
console.log(colors.toString());

Output:

red,blue,green

join() – The join() method works same as toString(). It is used to join all array elements into a string, but in addition, you can specify the separator.
Example:

let colors = ['red','blue','green'];
console.log(colors.join("+"));

Output:

red+blue+green

reverse() – The reverse() method is used to reverse the order of the elements in an array. It will change the original array and swap the order of the elements.
Example:

let fruits = ['mango','apple','grapes'];
console.log(fruits.reverse());

Output:


sort() – The sort() method is used to sort an array alphabetically. This function sorts the values as string by default.
Example:

let fruits = ['mango','apple','grapes'];
console.log(fruits.sort());

Output:


slice() – The slice() method is used to slice out a piece of an array into a new array. It creates a new array without removing any elements from the source array. It will return the value that has been sliced out from the array.
Example:

let colors = ['red','blue','green','yellow','orange'];
console.log(colors.slice(1,3));

Output:

These were some of the most commonly used JavaScript array methods. With this, we have come to the end of our article. I hope you understood how array methods are used in JavaScript.

#javascript #web-development #arrays #programming #developer

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All About JavaScript Arrays Methods

DJAMEL benali

1562496267

thank’s

Terry  Tremblay

Terry Tremblay

1602154740

Fill and Filter in Array in JavaScript

By the word Array methods, I mean the inbuilt array functions, which might be helpful for us in so many ways. So why not just explore and make use of them, to boost our productivity.

Let’s see them together one by one with some amazing examples.

Array.fill():

The _fill()_ method changes all elements in an array to a static value, from a start index (default _0_) to an end index (default _array.length_). It returns the modified array.

In simple words, it’s gonna fill the elements of the array with whatever sets of params, you pass in it. Mostly we pass three params, each param stands with some meaning. The first param value: what value you want to fill, second value: start range of index(inclusive), and third value: end range of index(exclusive). Imagine you are going to apply this method on some date, so that how its gonna look like eg: array.fill(‘Some date’, start date, end date).

NOTE: Start range is inclusive and end range is exclusive.

Let’s understand this in the below example-

//declare array
var testArray = [2,4,6,8,10,12,14];

console.log(testArray.fill("A"));

When you run this code, you gonna see all the elements of testArray will be replaced by 'A' like [“A”,"A","A","A","A","A","A"].

#javascript-tips #array-methods #javascript-development #javascript #arrays

Lowa Alice

Lowa Alice

1624388400

JavaScript Arrays Tutorial. DO NOT MISS!!!

Learn JavaScript Arrays

📺 The video in this post was made by Programming with Mosh
The origin of the article: https://www.youtube.com/watch?v=oigfaZ5ApsM&list=PLTjRvDozrdlxEIuOBZkMAK5uiqp8rHUax&index=4
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Thanks for visiting and watching! Please don’t forget to leave a like, comment and share!

#arrays #javascript #javascript arrays #javascript arrays tutorial

Tanya  Shields

Tanya Shields

1594911120

Learn Arrays And Array Methods in JavaScript

In JavaScript, an array is a data structure that contains list of elements which store multiple values in a single variable. The strength of JavaScript arrays lies in the array methods. Array methods are functions built-in to JavaScript that we can apply to our arrays — Each method has a unique function that performs a change or calculation to our array and saves us from writing common functions from scratch.
In this video we are going to learn arrays and array methods like sort(), reverse(), join(), split(), pop(), push(), shift(), unshift(), toString(), delete array, etc…

#javascript #arrays #array methods #programming

Madilyn  Kihn

Madilyn Kihn

1590478483

Convert String To Array Using Javascript Split Method

The easiest approach to use javascript built-in method String.split().

#javascript #javascript string #string to array #morioh #array

Rose Lancy

Rose Lancy

1596298980

9 Must Know JavaScript Array Methods

Arrays are one of the most common things that you’re going to use as a programmer. So, I’m going to explain nine JavaScript array methods that are going to make your life so much easier and more enjoyable.

To get started I just have an array of items, that we’re going to use for all these different array methods. Without wasting much time, let’s dive deep in to the pool of arrays (wink…)

const arrayItems = [
  {name: 'cheese cake', price: 25},
  {name: 'ham burger', price: 30},
  {name: 'cheesy tacos', price: 20},
  {name: 'beef burito', price: 18},
  {name: 'maxican chille rice', price: 15},
  {name: 'hot chocolate', price: 12},
  {name: 'apple frudge', price: 28},
  {name: 'chicken lassagna', price: 35},
]

filter() method

So let’s assume that we want to get all the items in this list that are less than or equal to 26 dollars of price. All we need to use is the filter method to filter out everything that’s under 26 dollars. So, let’s just say that, we have a variable which is going to be filteredItems. The filter method just takes a single function which is going to have one parameter.

const filteredItems = arrayItems.filter((item) => {
  return item.price <= 26;
})

#web-development #javascript #arrays #array-methods