Javascript Notes with examples - AGN HUB

  JavaScript Objects 1. What is a JavaScript Object? JavaScript objects are collections of key-value pairs. Keys (or properties) are strings, while values can be of any data type (numbers, strings, arrays, functions, or even other objects). Objects are used to store structured data. 2. Creating an Object There are multiple ways to create an object in JavaScript: (a) Using Object Literal let student = {     name: "John Doe",     age: 20,     course: "JavaScript",     isEnrolled: true }; console.log(student.name); // Output: John Doe (b) Using the new Object() Constructor let employee = new Object(); employee.name = "Alice"; employee.salary = 50000; console.log(employee.salary); // Output: 50000 (c) Using a Constructor Function function Car(brand, model, year) {     this.brand = brand;     this.model = model;     this.year = year; } let myCar = ...

  Events in javascript ==>mouse events 1. click - Triggered when a mouse button is clicked 2. dblclick - triggered when a mouse button is double-clicked 3. mousedown - Triggered when a mouse button is pressed down 4. mouseup - Triggered when mouse button is released 5. mouseover - Triggered when the mouse pointer enters an element 6. mouseout - Triggered when the mouse pointer leaves an element ==>keyboard events 1. keydown - Triggered when key is pressed down 2. keypress - Triggered when key is pressed and held down 3. keyup - Triggered when key is released ==>Form Events change - Triggered when the value of an input element changes input - similar like change event Triggered when the value of an input tag changes(more frequently) submit - Triggered when a form is submitted ==> window events 1. load - Triggered when a page and its depandent resources have finished loading 2. resize - Triggered when the browser window is resized 3. scroll - Triggered when the d...

  JavaScript Arrays  1. What is an Array? An array is a special variable in JavaScript that can hold multiple values in a single variable. It is an ordered collection of elements, accessible via index numbers. 2. Creating an Array Method 1: Using Square Brackets (Recommended) let fruits = ["Apple", "Banana", "Mango"]; console.log(fruits); Output: [ 'Apple', 'Banana', 'Mango' ] Method 2: Using the new Array() Constructor let numbers = new Array(10, 20, 30, 40); console.log(numbers); Output: [ 10, 20, 30, 40 ] 3. Accessing Array Elements Elements in an array are accessed using zero-based indexing . let colors = ["Red", "Green", "Blue"]; console.log(colors[0]); // First element console.log(colors[2]); // Third element Output: Red Blue 4. Modifying an Array You can change the value of an array element by accessing it via its index. let cars = ["BMW", "Audi", "Tesla"]; cars[1]...