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JavaScript is the world's most popular programming language.
JavaScript is the programming language of the Web.
JavaScript is easy to learn.
This tutorial will teach you JavaScript from basic to advanced.
JavaScript is a high-level, dynamic, interpreted programming language that is widely used for web development. It allows developers to create interactive and dynamic elements on webpages, making websites more engaging and user-friendly. JavaScript can be run on the client side (in the user's web browser) as well as on the server side (using technologies like Node.js).
Key features and characteristics of JavaScript include:
Interactivity: JavaScript enables developers to create interactive features such as form validation, animations, and real-time updates on webpages.
Dynamic Content: It can be used to manipulate the Document Object Model (DOM), allowing for the addition, removal, or modification of HTML and CSS content on-the-fly.
Event Handling: JavaScript can respond to user actions, such as clicks, keyboard input, and mouse movements, by triggering specific functions or behaviors.
Asynchronous Programming: JavaScript supports asynchronous programming through features like callbacks, Promises, and async/await, allowing for non-blocking execution of code and smooth handling of tasks like fetching data from servers.
Cross-Platform: JavaScript can be executed on various platforms, including different web browsers and server environments, making it a versatile language.
Client-Side and Server-Side: JavaScript was originally designed for client-side scripting within web browsers, but with the advent of technologies like Node.js, it can also be used for server-side programming.
Open Source and Community-Driven: JavaScript is an open-source language with a large and active developer community. This community contributes to the development of frameworks, libraries, and tools that extend its capabilities.
Ecosystem: JavaScript has a vast ecosystem of libraries (such as jQuery, React, and Angular) and tools that simplify and accelerate web development tasks.
Weakly Typed: JavaScript is a loosely typed language, meaning that variable types can change dynamically during runtime.
Prototype-Based Inheritance: JavaScript uses a prototype-based object-oriented programming model, allowing objects to inherit properties and methods from other objects.
JavaScript is an essential component of modern web development and is used alongside HTML and CSS to create interactive and visually appealing websites. It has become one of the most popular and widely used programming languages, playing a pivotal role in shaping the user experience of the modern web.
Why we have to learn JavaScript?
JavaScript stands as one of the three essential languages that every web developer should master:
HTML (Hypertext Markup Language): Used to structure and present the content of web pages.
CSS (Cascading Style Sheets): Utilized to design and style the layout and appearance of web pages.
JavaScript: Employed to program the behavior and interactivity of web pages, creating dynamic and responsive user experiences.
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Common question asked in JavaScript interview are:
1.From Where I get JavaScript?
You don’t need to download or install JavaScript
2.From where you can download JavaScript?
JavaScript have already known by your browser so you can run it easily
JavaScript Popup Boxes:
its a part of BOM(Browser Object Model)
JavaScript has three kind of popup boxes:
1. Alert box
2. Confirm box
3. Prompt box
Confirm and prompt boxes are interactive dialog boxes in JavaScript used to interact with users and obtain information or confirmation from them.
Confirm Box: A confirm box displays a message to the user along with two buttons: OK and Cancel. It is commonly used to confirm an action before proceeding. When the user clicks OK, the confirm box returns true. If the user clicks Cancel, it returns false.
Prompt Box: A prompt box displays a message to the user along with a text input field and two buttons: OK and Cancel. It is used to prompt the user to enter some information or value. The user can type a response into the input field. When the user clicks OK, the prompt box returns the value entered by the user as a string. If the user clicks Cancel, it returns null.
The CSS property "font-size" is used to specify the size of the font in an element. It determines the height of the font characters, affecting the overall appearance and readability of text content on a webpage.
Syntax: font-size: value;
The value can be specified in various units such as pixels (px), points (pt), ems (em), percentages (%), or relative units like rem (root em) and vw (viewport width).
Pixels (px) is the most commonly used unit and represents the size of the font in pixels on the screen.
Points (pt) are commonly used in print media and represent 1/72 of an inch.
Ems (em) represent the font size relative to the parent element's font size. For example, a font-size of 1em is equal to the font size of the parent element.
Percentages (%) represent the font size relative to the font size of the parent element.
Relative units like rem and vw provide scalability and adaptability to different screen sizes.
The JavaScript calculator is a web-based application that allows users to perform mathematical calculations directly within their web browser. It provides a user-friendly interface with buttons for numbers, operators, and other functions, similar to a physical calculator.
Key features of a JavaScript calculator include:
User Interface: The calculator has a graphical user interface (GUI) consisting of buttons for digits 0-9, arithmetic operators (+, -, *, /), decimal point, clear (C), and equals (=) button to perform calculations.
Responsive Design: The calculator is designed to be responsive, meaning it adjusts its layout and size to fit different screen sizes and devices, including desktops, tablets, and smartphones.
Input Handling: It can handle user input either through button clicks or keyboard input. Users can enter numbers and perform calculations using the mouse or keyboard.
Arithmetic Operations: The calculator supports basic arithmetic operations such as addition, subtraction, multiplication, and division. It also handles more complex calculations involving parentheses and operator precedence.
Error Handling: The calculator includes error handling to prevent invalid input and display error messages for division by zero or other mathematical errors.
Memory Functions: Some calculators may include memory functions such as memory recall (MR), memory clear (MC), memory addition (M+), and memory subtraction (M-) to store and retrieve intermediate results.
Scientific Functions (Optional): Advanced calculators may include scientific functions such as square root, exponentiation, trigonometric functions (sine, cosine, tangent), logarithms, and factorial.
History Display: The calculator may have a history display area to show previous calculations and results, allowing users to review their calculations or copy them for reference.
JavaScript Display Possibilities
JavaScript can "display" data in different ways:
Writing into an HTML element, using innerHTML.
Writing into the HTML output using document.write().
Writing into an alert box, using window.alert().
Writing into the browser console, using console.log().