DEV Community: Piyush Panchal

const vs. let

Piyush Panchal — Mon, 15 Feb 2021 10:07:04 +0000

In JavaScript, There are three ways of declaring a variable, why though? How are they different? const cannot be redeclared. therefore it will have one constant value, and can't be changed. For Example-

const number = 1

number = 2
//Gives an error (const cannot be redefined.)

Whereas let can be changed anytime. For example-

let num = 2

num = 5

//Value changes to 5 with no errors.

Thanks for reading.
Hope I helped :D

What's the difference between map() and forEach() in JS?

Piyush Panchal — Sat, 13 Feb 2021 16:00:03 +0000

Arrays are super useful and widely used data structures. It also has a ton of different functions which can make our work so much easier. The functions that many people get confused about is map() and forEach() and it's reasonable both do almost the same thing. I personally made this mistake so many times when I was a beginner. The similarity is- that they both run a function or a piece of code for each of the element of the array. But forEach() does not return any new array. It just runs the code for the elements. map() on the other hand returns a new array with the result. Hope this helped.

Thanks for reading.

Hi there!

Piyush Panchal — Sat, 13 Feb 2021 15:36:56 +0000

Hello! I am Piyush Panchal, I am currently a Student. I am a Web Developer, mainly focusing on JavaScript, React and NodeJS. Hope to find and write good articles!

Thanks!