Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Economics & Finance
Displaying millions of rows efficiently requires JavaScript grids that use virtual rendering techniques. These grids only render visible rows in the DOM, dramatically improving performance compared to traditional approaches that render all data at once. Popular Data Grids for Large Datasets S. No Grid Description Max Rows ... Read More
To set a dotted line for the border in CSS, use the border-style property with the value dotted. This creates a border made up of small dots around the element. Syntax border-style: dotted; Example Here's how to create a dotted border using CSS: .dotted-border { border-width: 3px; ... Read More
There are two methods to modify properties of nested objects in JavaScript. One is Dot notation and the other is Bracket notation. The functionality is the same for both methods, but they differ in their syntax and use cases. Let's discuss them in detail with practical examples. Dot Notation Method Dot notation is the most common way to access and modify nested object properties. Use this when property names are valid identifiers and known at compile time. Example In the following example, initially the value of property country is England. Using dot notation, the value ... Read More
In JavaScript, the extends keyword enables class inheritance, allowing you to create child classes that inherit properties and methods from parent classes. This is a fundamental feature of ES6 classes that promotes code reusability and establishes clear hierarchical relationships between classes. Class inheritance allows you to build upon existing functionality without rewriting code. The child class automatically gains access to all public methods and properties of its parent class, while still being able to add its own unique features or override inherited behavior. Syntax class ChildClass extends ParentClass { // Child class ... Read More
Importing objects with nested sub-objects and arrays in JavaScript using ES6 modules allows for modular code organization. This technique is essential for sharing complex data structures between different JavaScript files. What are ES6 Modules? ES6 modules use export and import statements to share code between files. The export default syntax allows exporting a single object, function, or value as the default export from a module. Example: Importing Complex Objects Let's create a complete example showing how to import an object containing nested objects and arrays. sample.js (Module file) export default { ... Read More
Let's say, we have an array of objects like this – const arr = [ {"name1": "firstString"}, {"name2": "secondString"}, {"name3": "thirdString"}, {"name4": "fourthString"}, {"name5": "fifthString"}, {"name6": "sixthString"}, ]; We are required to write a function that takes one such array of objects and returns an object with all the properties listed in that object. So, let's write the code for this function. It can be done through the Array reduce method – Using Array.reduce() Method ... Read More
We have an array of arrays like this − const arr = [ ['foo', 'bar', 'hey', 'oi'], ['foo', 'bar', 'hey'], ['foo', 'bar', 'anything'], ['bar', 'anything'] ] We are required to write a JavaScript function that takes in such array and returns an array that contains all the strings which appears in all the subarrays. Let's write the code for this function Example const arr = [ ['foo', 'bar', 'hey', 'oi'], ['foo', 'bar', 'hey'], ... Read More
To get sequence numbers in loops with JavaScript, you can use various approaches. The most common method is maintaining a counter variable that increments with each iteration. Using forEach() with External Counter The forEach() method provides an elegant way to iterate through arrays while maintaining sequence numbers using an external counter: let studentDetails = [ { id: 101, details: [{name: 'John'}, {name: 'David'}, {name: 'Bob'}] }, { ... Read More
We are required to write a JavaScript function that takes in two numbers, say m and n, and it returns an array of first n multiples of m. For example − If the numbers are 4 and 6 Then the output should be − const output = [4, 8, 12, 16, 20, 24] Example Following is the code − const num1 = 4; const num2 = 6; const multiples = (num1, num2) => { const res = []; for(let i = num1; i ... Read More
In this tutorial, we will learn how to pad a number with leading zeros in JavaScript. Padding a number can be done in different ways in JavaScript. In this tutorial, we will see the two most popular ways of doing it − Using the String padStart() method Using the Array object constructor and join() method Using the String padStart() Method In JavaScript, the String object's padStart() method is useful to pad a number with leading zeros. It takes two parameters, the first one is the total length of the targeted or ... Read More