Find an item in an array with the ‘findIndex’ method in JavaScript.
The
findIndex()
method returns the index of the first element of the array if the callback function passed to thefindIndex
method returns true, otherwise returns -1
Syntax
arr.findIndex(callback( element, index, array ) ,thisArg)
callback function
→ A function to execute on each value in the array until the function returns true
, indicating that the satisfying element was found.thisArg
→ Optional object to use as this
when executing callback
.The callback function
takes three arguments
element
→ current processing elementindex (Optional)
→ index of the element…Learn how to improve the performance of rendering in canvas by using OffscreenCanvas
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
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
.
preventExtensions
method returns the object being made non-extensible.extensible
again once it has been made non-extensible
.non-extensible
we can use Object.isExtensible()
preventExtensions()
method only prevents addition of own properties. …Understanding the Split Method in JavaScript
The split
method spilt the string into array of substring based on the pattern provided.
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…
XHR
)?XMLHttpRequest
is an in-built JavaScript object that is used to transfer data between a server and a client without refreshing the whole page.XHR
we can update the page based on the user action.XHR
, we can make both synchronous and asynchronous requests.XMLHttpRequest
object.let request = new XMLHttpRequest();
To configure the…
Learn to check if the primitive value or object present in an array in JavaScript
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];
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.
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 :
Google pay: 8015851838.
Thank you so much for your time
These are the articles that are freshly created this week. I hope you like this
Detect network online/offline State using JavaScript
One-Time Event Listener in JavaScript
Asynchronous Image Loading in JavaScript
Difference between append and appendChild method
Inserting elements in JavaScript Array
Learn how to generate ASCII art from the image using Python.
Steps to convert image to ASCII character
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. …
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