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Articles by AmitDiwan
Page 433 of 840
How to add a property, method to a JavaScript constructor?
In JavaScript, you can add properties and methods to constructor functions using the prototype property. This allows all instances of the constructor to share these additions. Syntax // Add a property ConstructorName.prototype.propertyName = value; // Add a method ConstructorName.prototype.methodName = function() { // method body }; Example: Adding Property and Method to Constructor Document body { font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif; } ...
Read MoreHow to change an object Key without changing the original array in JavaScript?
When working with arrays of objects in JavaScript, you often need to change object keys while preserving the original data structure. This tutorial shows how to rename object keys without mutating the original array. The Problem Directly modifying object properties changes the original array, which can cause issues in applications that rely on immutable data patterns. Method 1: Using map() with Object Destructuring The most elegant approach uses destructuring to extract the old key and create a new object: Change Object Key Change Object Key Without Mutating ...
Read MoreConverting Odd and Even-indexed characters in a string to uppercase/lowercase in JavaScript?
We need to write a function that reads a string and converts the odd indexed characters in the string to upperCase and the even ones to lowerCase and returns a new string. Understanding Index-Based Case Conversion In JavaScript, string indices start at 0. Even indices (0, 2, 4...) will be converted to lowercase, while odd indices (1, 3, 5...) will be converted to uppercase. Example const text = 'Hello world, it is so nice to be alive.'; const changeCase = (str) => { const newStr = str ...
Read MoreGenerate colors between #CCCCCC and #3B5998 for a color meter with JavaScript?
We have to write a function that generates a random color between two given colors. Let's tackle this problem in parts − First → We write a function that generates a random number between two given numbers. Second → Instead of using the hex scale for random color generation, we will map the hex to 0 to 15 decimal scale and use that instead. ...
Read MoreIs an empty iframe src valid in JavaScript?
An empty iframe src can be handled in JavaScript using about:blank or by leaving the src attribute empty. The about:blank approach is more reliable and creates a valid, blank document. Valid Approaches for Empty iframe src There are several ways to create an empty iframe: Using about:blank (Recommended) The about:blank value creates a valid empty document that can be safely manipulated with JavaScript: Empty iframe Example ...
Read MoreCreating JavaScript constructor using the "new" operator?
In JavaScript, constructor functions create objects using the new operator. A constructor function is a regular function that becomes a template for creating multiple objects with similar properties. Syntax function ConstructorName(param1, param2) { this.property1 = param1; this.property2 = param2; } // Create new object let obj = new ConstructorName(value1, value2); Example JavaScript Constructor body ...
Read MoreHow to pass event objects from one function to another in JavaScript?
In JavaScript, event objects contain information about user interactions like clicks, key presses, or mouse movements. You can pass these event objects between functions to share event data and manipulate the same target element across multiple functions. Syntax // Function that receives event and passes it to another function firstFunction(event) { // Do something with event secondFunction(event); // Pass event to another function } function secondFunction(event) { // Use the same event object event.target.style.property = "value"; } ...
Read MoreReturning values from a constructor in JavaScript?
In JavaScript, constructors typically don't need explicit return statements since they automatically return the newly created object. However, you can override this behavior by explicitly returning an object from a constructor. How Constructor Returns Work When you use the new keyword with a constructor: If the constructor returns an object, that object becomes the result If the constructor returns a primitive value (string, number, boolean), it's ignored and this is returned instead If there's no explicit return, this is returned automatically Example: Returning an Object from Constructor ...
Read MoreHow do we loop through array of arrays containing objects in JavaScript?
In JavaScript, when working with nested arrays containing objects, you need to use nested loops to access each object's properties. This tutorial demonstrates multiple approaches to iterate through such complex data structures. Understanding the Data Structure An array of arrays containing objects has this structure: let arrObj = [ [ { name: "Rohan", age: 22 }, { name: "Mohan", age: 12 } ], [ ...
Read MoreOrder items alphabetically apart from certain words JavaScript
In JavaScript, you can sort an array alphabetically while keeping certain priority words at the top. This is useful when you need specific items to appear first, regardless of alphabetical order. Let's create a function excludeSort(arr, ex) where arr is the array to be sorted and ex contains the priority words that should appear at the top. How It Works The sorting logic uses a custom comparator that: Places priority words (from ex array) at the top Sorts remaining words alphabetically Uses Array.includes() to check if a word is in the priority list Example ...
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