Filter( ) in JavaScript

·

2 min read

Filter() is a method in JavaScript that can effortlessly provide filtered output data(in the form of array) by processing an array

Here's the syntax of the filter() method:

let newArray = arr.filter(callback(element[, index[, array]])[, thisArg])

In this syntax:

  • newArray: This is the new array that will be returned by the filter() method.

  • arr: This is the original array on which the filter() method was called.

  • callback: This is a function that tests each element of the array. Return true to keep the element, false otherwise. It accepts three arguments:

    • element: The current element being processed in the array.

    • index (optional): The index of the current element being processed in the array.

    • array (optional): The array filter() was called upon.

  • thisArg (optional): Value to use as this when executing callback.

Here's a simple example:

const numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];

const filteredNumbers = numbers.filter((number) => number % 2 === 0);

console.log(filteredNumbers); // Output: [2, 4, 6, 8, 10]

In this example, the filter() method is used to filter out the even numbers from the numbers array. The new evenNumbers array is then logged to the console.

Thank you for reading. I encourage you to follow me on Twitter where I regularly share content about JavaScript and React, as well as contribute to open-source projects. I am currently seeking a remote job or internship.

Twitter: https://twitter.com/Diwakar_766

GitHub: https://github.com/DIWAKARKASHYAP

Portfolio: https://diwakar-portfolio.vercel.app/