Condo Mark

Condo Mark


4 big differences between forEach vs. map in JavaScript

JavaScript has some methods that help us to iterate through Arrays. The two most used are **foreach()** and **map()** in Javascript. But I believe there is a lot of doubt between these two methods.

Because they both do some iteration. So, what’s the difference?

Table of Contents

  • forEach and map in Javascript: Definitions
  • The method’s return
  • Ability to chain with other methods
  • Mutability
  • Performance
  • The Bottom line


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4 big differences between forEach vs. map in JavaScript

Pravin Kumar


Found very useful. Thanks for sharing

Samanta  Moore

Samanta Moore


Java Vs. JavaScript: Know the Difference

What a mess it could be to share the same name — especially if you are a programming language. Even if you are already over 20 years old, IT newbies periodically confuse you with your namesake. This happens all the time with Java and JavaScript, although they are not related at all! As someone on the internet said. They correlate in much the same way as a car and a carpet.

Why do these two languages have such similar names? How do they differ from each other, and what else do they have in common? This article will provide the answers to these questions.

In the Beginning, It Was Java

The Same Year, A Little Bit Later: Meet JavaScript!

Technical Differences Between Java and JavaScript

What Can You Build in Java and JavaScript?

#java #javascript #javascript-development #java-development #learn-to-code-java #learn-javascript #programming #java-vs-javascript

4 big differences between forEach and map in JavaScript

JavaScript has some methods that help us to iterate through Arrays. The two most used are foreach() and map() in Javascript. But I believe there is a lot of doubt between these two methods.

forEach and map in Javascript: Definitions

We will define each method, and where each one fits in, to try to understand better what we can do with each one:

The map() method gets a function as a parameter. This function is invoked for each Array element and, at the end, the method returns a completely new array filled with the results of the given function call.

const numbers = [5, 4, 3, 2, 1]

console.log( => element * element)) //[ 25, 16, 9, 4, 1 ]

This means that it returns a new array that contains an image of each array element. It will always return the same number of items.

The forEach() method receives a function as an argument and executes it once for each Array element. However, instead of returning a new array as the map() method, it returns undefined.

const numbers = [5, 4, 3, 2, 1]

console.log(numbers.forEach(element => element * element)) //undefined

#javascript #programming #foreach

Mahipal Nehra

Mahipal Nehra


Java vs. JavaScript: Know The Difference

Java vs. JavaScript

#java #javascript #Java vs. JavaScript #Java vs JavaScript #programming

Gerhard  Brink

Gerhard Brink


Data Science vs Big Data: Difference Between Data Science & Big Data

In the digital era that we live in, data has become the biggest and most valuable asset for most organisations. Data is rapidly transforming the way we live and communicate, and it is by collecting, sorting and studying this data, that organisations across the world are looking for ways to impact their bottom lines.

When working with all terminology related to data, it is essential to have a clear understanding of the different scope of work related to it. In this article, we’ll discuss the differences between Big Data and Data Science. Though these terms are interlinked and often used interchangeably, there’s a vast underlying difference between them in all aspects.

Let us begin by defining the two terms.

Big Data is a standard way to define it is as an assortment of data which is too large to be stored or processed using the traditional database systems within a given period. A common misconception while referring to it is when the term is used to refer to data whose size of the volume is of the order of terabytes or more. However, it is a purely contextual term. For example, even a file of 250MB is Big Data in the context of an email attachment.

Data exhibits key attributes that must be taken into consideration when processing a dataset. They are most commonly known as the 5 Vs. Each of the Vs has specific implications in terms of handling them, but, when all of them are seen in combination, they present even bigger challenges.

#big data #big data vs data science #comparison #data science #difference between big data and data science

Coy  Roberts

Coy Roberts


Javascript Array forEach() Method Example

Javascript array foreach is an inbuilt function that can be used to execute a function on each item in the array. The forEach() method is called on the array Object and is passed the function that is called on each item in the array.  The  callback function can also take the second parameter of the index in case you need to reference the index of the current element in the array.

Understanding Javascript Array forEach

In a nutshell, Javascript forEach() method executes a provided function once for each array element. Javascript forEach only be used on the Arrays, Maps, and  Sets. This article briefly describes how to use the forEach() method to iterate the items of the array in JavaScript.

What’s the usual thing you do with an  array? Add or remove items from an array. Iterate through its items! This is where the forEach() array method shines.

Before we dive into seeing how forEach() works, we need to take a look at how looping works. Looping is a fundamental computer science concept. If you want to be a sound programmer, mastering loops are amidst the first steps you need to take.

Here’s an example of a for loop in Javascript.

let languages = ['Python', 'Javascript', 'PHP', 'Golang'];

for (i = 0; i < languages.length; i++) {

#javascript #javascript array foreach #javascript foreach