Find an item in an array with the ‘findIndex’ method in JavaScript.

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The findIndex() method returns the index of the first element of the array if the callback function passed to the findIndex method returns true, otherwise returns -1

Syntax

arr.findIndex(callback( element, index, array ) ,thisArg)

The callback function takes three arguments


Learn how to improve the performance of rendering in canvas by using OffscreenCanvas

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The OffscreenCanvas interface allows canvas rendering contexts (2D and WebGL) to be used in Workers. It increases parallelism in the web, leading to improved performance on multi-core systems.

Using OffscreenCanvas we can render a canvas in the worker thread so that the main thread will be undisturbed so that our web app will work smoothly.

The support of OffscreenCanvas across the browser can be found here CanIUse.

There are two ways we can use OffscreenCanvas


Learn how to use preventExtensions to stop adding new properties to a JavaScript Object

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Photo by Dan-Cristian Pădureț on Unsplash

The Object.preventExtensions() method prevents new properties from added to an object.

In the above code, after calling preventExtensions on the user object, when we try to add age property JavaScript will thow TypeError .


Understanding the Split Method in JavaScript

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Image taken here.

The split method spilt the string into array of substring based on the pattern provided.

Example

let numbersStr = "1,2,3,4,5";let numArray = numbersStr.split(",");console.log(numArray); // ["1","2","3","4","5"]

In the above example , the split method will loop through all the character of the string , if the pattern provided is found then the split method will collect the characters looped before finding the pattern and join all the characters as a string and pushed that string into an array .

If we don’t pass any pattern then the entire string will be pushed to an…


Learn how to make requests using XMLHttpRequests

summary of key XMLHttpRequest commands covered in this article
summary of key XMLHttpRequest commands covered in this article
Image source: Author

What Is XMLHttpRequest (XHR)?

Steps to Make a Request Using XMLHttpRequest

1. Create a XMLHttpRequest object

let request = new XMLHttpRequest();

2. Configure the object with request details

To configure the…


Learn to check if the primitive value or object present in an array in JavaScript

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Photo by Deva Darshan on Unsplash

Checking if a primitive value present in an array

You can use

method to check if a primitive value present in an array, Consider we have an array

var num = [1,2,3,4,5];

indexOf

The indexOf() method returns the first index of the element in the array, if the searching element is not present in the array then it returns -1 .

num.indexOf(3); // 2num.indexOf(6); //-1num.indexOf('3'); // -1

The NaN value is not handled in indexOf method.

var array = [NaN];array.indexOf(NaN); // -1

If your array can…


Requesting donation for my Badminton Training.

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Image by Vladislav

Hello Reader, My name is Jagathish Saravanan, I am from India. I am currently working as a Web developer , I love my Job , but once I started playing Badminton , I started loving Badminton more that anything , So I have decided to switch my carrer to Badminton, It is hard to manage my training expense , so I started writing Blog in Medium . But medium partner program is not supported in India. So I am requesting you to donate some amount .

You can donate me in PayPal :

https://paypal.me/jagathishSaravanan?locale.x=en_GB

Google pay: 8015851838.

Thank you so much for your time


Learn how to generate ASCII art from the image using Python.

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Generated in Python

Steps to convert image to ASCII character

Loading an Image using PIL image Library

To load the image we will be using PIL library.

import PIL.Image

def main():
path = input("Enter the path to the image fiel : \n")
try:
image = PIL.Image.open(path)
except:
print(path, "Unable to find image ");

The above code reads the image from the path given by the user. …

Javascript Jeep🚙💨

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