JavaScript

Here are five ways to create an empty array of a given size in JavaScript. Using the new operator (Array constructor) Using the spread operator Using Array.fill() method Using Array.from() method Using apply() and map() Method 1: Using the new operator (Array constructor) The easiest way to create an empty array of a given size … Read more

Here are three ways to check if an array index exists in JavaScript. Using the in operator Checking against undefined Using the hasOwnProperty method Method 1: Using the in operator The in operator in JavaScript returns true if the specified property/index exists and false otherwise. let arr = [10, 20, 30]; console.log(1 in arr); console.log(5 … Read more

Here are two primary ways to create an empty Object in JavaScript. Using the Object Literal syntax ({ }) Using the Object Constructor (new Object()) Method 1: Using the Object Literal syntax ({ }) The most easy and clean way to create an empty Object in JavaScript is to use the Object literal syntax ({ … Read more

Here are two ways to convert JSON String to an Array of JSON Objects in JavaScript. Using JSON.parse( ) Using eval() Let’s check out both methods one by one. Method 1: Using JSON.parse() The JSON.parse() method is recommended to convert a JSON string into a JavaScript object or array. It’s safe, efficient, and specifically designed … Read more

The fastest way to convert NodeList to Array in JavaScript is to use the “Array.prototype.from()” method. The Array.prototype.from() method is used to create a shallow-copied new Array instance from an array-like or iterable object. Syntax let main_arr = Array.from(nodelist) Example let nodelist = document.querySelectorAll(‘div’); let main_arr = Array.from(nodelist); console.log(main_arr); for (let val of main_arr) { … Read more

Here are two ways to find the first element of an array matching a condition in JavaScript. Using Array.prototype.find() Using Array.prototype.filter() Method 1: Using Array.prototype.find() To find the first element of an array matching a condition in JavaScript, use the “Array.prototype.find()” method. The find() method accepts a callback function as its argument and returns the … Read more

Here are two ways to check if an array of strings contains a substring in JavaScript. Using includes() method and some() method Using includes() method and filter() method Method 1: Using includes() method and some() method The some() method is used to check whether at least one element in the array passes the test implemented … Read more

The most efficient way to create a zero filled array in JavaScript is to use the “Array.fill() method.” The Array.fill() method is used to fill all the elements of an array with a static value, which is 0 in this case. Syntax arr(length).fill(value) Example 1: Using the Array.fill() method const length = 5; const zeroFilledArray = … Read more

Here are three ways to convert a Map to an Array in JavaScript. Using the “Array.from()” and “Map.keys()” Using the “Spread operator” and “Map.keys()” Using “for..of loop” Method 1: Using the Array.from() and Map.keys() The Array.prototype.from() method creates a new array instance from an iterable object, such as a Map. It can conjunction with the … Read more

Here are three ways to return the response from an Asynchronous Call in JavaScript. Promises with async/await (ES2017+) Promises with then() (ES2015+) Callback function Method 1: Promises with async/await (ES2017+) The ECMAScript version released in 2017 introduced syntax-level support for asynchronous functions. With the help of async and await, you can write asynchronous code in … Read more