Rachel Cole

Rachel Cole


Top 10 JavaScript Array Methods You Should Know

In this post i will share 10 JavaScript array methods you should know.

If you know nothing about array, you can click here for array introduction.

Here are 10 javascript array methods you should at least know

1. forEach()

This method can help you to loop over array’s items.

  const arr = [1, 2, 3, 4, 5, 6];

  arr.forEach(item => {
    console.log(item); // output: 1 2 3 4 5 6

2. includes()

This method check if array includes the item passed in the method.

  const arr = [1, 2, 3, 4, 5, 6];

  arr.includes(2); // output: true
  arr.includes(7); // output: false

3. filter()

This method create new array with only elements passed condition inside the provided function.

  const arr = [1, 2, 3, 4, 5, 6];

  // item(s) greater than 3
  const filtered = arr.filter(num => num > 3);
  console.log(filtered); // output: [4, 5, 6]

  console.log(arr); // output: [1, 2, 3, 4, 5, 6]

4. map()

This method create new array by calling the provided function in every element.

  const arr = [1, 2, 3, 4, 5, 6];

  // add one to every element
  const oneAdded = arr.map(num => num + 1);
  console.log(oneAdded); // output [2, 3, 4, 5, 6, 7]

  console.log(arr); // output: [1, 2, 3, 4, 5, 6]

5. reduce()

The reduce() method applies a function against an accumulator and each element in the array (from left to right) to reduce it to a single value - MDN

  const arr = [1, 2, 3, 4, 5, 6];

  const sum = arr.reduce((total, value) => total + value, 0);
  console.log(sum); // 21

6. some()

This method check if at least one of array’s item passed the condition. If passed, it return ‘true’ otherwise ‘false’.

  const arr = [1, 2, 3, 4, 5, 6];

  // at least one element is greater than 4?
  const largeNum = arr.some(num => num > 4);
  console.log(largeNum); // output: true

  // at least one element is less than or equal to 0?
  const smallNum = arr.some(num => num <= 0);
  console.log(smallNum); // output: false

7. every()

This method check if all array’s item passed the condition. If passed, it return ‘true’ otherwise ‘false’.

  const arr = [1, 2, 3, 4, 5, 6];

  // all elements are greater than 4
  const greaterFour = arr.every(num => num > 4);
  console.log(greaterFour); // output: false

  // all elements are less than 10
  const lessTen = arr.every(num => num < 10);
  console.log(lessTen); // output: true

8. sort()

This method used to arrange/sort array’s item either ascending or descending order.

  const arr = [1, 2, 3, 4, 5, 6];
  const alpha = ['e', 'a', 'c', 'u', 'y'];

  // sort in descending order
  descOrder = arr.sort((a, b) => a > b ? -1 : 1);
  console.log(descOrder); // output: [6, 5, 4, 3, 2, 1]

  // sort in ascending order
  ascOrder = alpha.sort((a, b) => a > b ? 1 : -1);
  console.log(ascOrder); // output: ['a', 'c', 'e', 'u', 'y']

9. Array.from()

This change all thing that are array-like or iterable into true array especially when working with DOM, so that you can use other array methods like reduce, map, filter and so on.

  const name = 'frugence';
  const nameArray = Array.from(name);

  console.log(name); // output: frugence
  console.log(nameArray); // output: ['f', 'r', 'u', 'g', 'e', 'n', 'c', 'e']

working with DOM

  // I assume that you have created unorder list of items in our html file.

  const lis = document.querySelectorAll('li');
  const lisArray = Array.from(document.querySelectorAll('li'));

  // is true array?
  console.log(Array.isArray(lis)); // output: false
  console.log(Array.isArray(lisArray));  // output: true

10. Array.of()

This create array from every arguments passed into it.

  const nums = Array.of(1, 2, 3, 4, 5, 6);
  console.log(nums); // output: [1, 2, 3, 4, 5, 6]

#javascript #web-development #programming #developer

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Top 10 JavaScript Array Methods You Should Know
Terry  Tremblay

Terry Tremblay


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.


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];


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


JavaScript Arrays Tutorial. DO NOT MISS!!!

Learn JavaScript Arrays

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The origin of the article: https://www.youtube.com/watch?v=oigfaZ5ApsM&list=PLTjRvDozrdlxEIuOBZkMAK5uiqp8rHUax&index=4
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#arrays #javascript #javascript arrays #javascript arrays tutorial

Lokesh Kumar


Top 10 Trending Technologies Must Learn in 2021 | igmGuru

Technology has taken a place of more productiveness and give the best to the world. In the current situation, everything is done through the technical process, you don’t have to bother about doing task, everything will be done automatically.This is an article which has some important technologies which are new in the market are explained according to the career preferences. So let’s have a look into the top trending technologies followed in 2021 and its impression in the coming future in the world.

  1. Data Science
    First in the list of newest technologies is surprisingly Data Science. Data Science is the automation that helps to be reasonable for complicated data. The data is produces in a very large amount every day by several companies which comprise sales data, customer profile information, server data, business data, and financial structures. Almost all of the data which is in the form of big data is very indeterminate. The character of a data scientist is to convert the indeterminate datasets into determinate datasets. Then these structured data will examine to recognize trends and patterns. These trends and patterns are beneficial to understand the company’s business performance, customer retention, and how they can be enhanced.

  2. DevOps
    Next one is DevOps, This technology is a mixture of two different things and they are development (Dev) and operations (Ops). This process and technology provide value to their customers in a continuous manner. This technology plays an important role in different aspects and they can be- IT operations, development, security, quality, and engineering to synchronize and cooperate to develop the best and more definitive products. By embracing a culture of DevOps with creative tools and techniques, because through that company will gain the capacity to preferable comeback to consumer requirement, expand the confidence in the request they construct, and accomplish business goals faster. This makes DevOps come into the top 10 trending technologies.

  3. Machine learning
    Next one is Machine learning which is constantly established in all the categories of companies or industries, generating a high command for skilled professionals. The machine learning retailing business is looking forward to enlarging to $8.81 billion by 2022. Machine learning practices is basically use for data mining, data analytics, and pattern recognition. In today’s scenario, Machine learning has its own reputed place in the industry. This makes machine learning come into the top 10 trending technologies. Get the best machine learning course and make yourself future-ready.

To want to know more click on Top 10 Trending Technologies in 2021

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How to Become a Salesforce Developer

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#top trending technologies #top 10 trending technologies #top 10 trending technologies in 2021 #top trending technologies in 2021 #top 5 trending technologies in 2021 #top 5 trending technologies

Rose Lancy

Rose Lancy


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

Tanya  Shields

Tanya Shields


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