JavaScript – Introduction
JavaScript initially called as “Live Script” where it makes the “web pages alive”. In JavaScript the engine (embedded if it’s a browser) reads (“parses”) the script, then it converts (“compiles”) the script to the machine language and then the machine code runs, pretty fast.
It is a high-level, interpreted programming language and can update and change both HTML and CSS and it can even calculate, manipulate and validate data. The programs in this language are called scripts. They can be written right in the HTML and executed automatically as the page loads.It is a “safe” programming language, it does not provide low-level access to memory or CPU, as it was initially created for browsers which do not require it.
JavaScript variables are Numbers, Strings, Objects, Arrays, and Functions. It is one of the three core technologies of the World Wide Web and enables interactive web pages and thus is an essential part of web applications. Many websites use it and all major web browsers have a dedicated JavaScript engine to execute it.
JavaScript Designed by Brendan Eich
Javascript is a MUST for students and working professionals to become a great Software Engineer especially when they are working in Web Development Domain.
- Javascript is a programming language that conforms to the ECMAScript
- javascript enables interactive web pages (alongside HTML and CSS )and is an essential part of web applications.
- Most majority of websites use it for client-side page behavior, and all major web browsers have a dedicated JavaScript engine to execute it.
- JavaScript engines were originally used only in web browsers but now embedded in some servers, usually via Node.js.
NOTE: JavaScript and Java, the two languages differ greatly in design.
JavaScript language is mainly used for enhancing the interaction of a user with the webpage or website. In other words, you can make your webpage or website more lively and interactive, with the help of JavaScript. JavaScript is also being used widely in Mobile application and game development.
Features of JavaScript:
- It is a light-weighted and interpreted language.
- It is a case-sensitive language.
- It is supportable in several operating systems( including, Windows, macOS, etc).
- Good control to the users over the web browsers.
- All popular web browsers support JavaScript.
Application of JavaScript:
- Client-side validation.
- Dynamic drop-down menus.
- Displaying pop-up windows and dialog boxes.
- Displaying date and time etc.
Example:
<html>
<body>
<h2>Welcome to JavaScript</h2>
<script>
document.write("JavaScript was developed by Brendan Eich in 1995");
</script>
</body>
</html>
OUTPUT:
