JavaScript was developed by the erstwhile Netscape Communications Corporation, which developed the Netscape browser, one of the first browsers built to navigate the World Wide Web in the mid-1990s. In the late 1990s, however, the Web was just beginning to get popular, and Netscape gradually captured 90% of the market before eventually losing out to Microsoft’s Internet Explorer at the turn of the century. As JavaScript was the de facto language used by Netscape for client-side scripting, it became, and continues to be, the gold standard for Web application development. Today, you will find tons of literature and numerous programs if you wish to learn about the language.
JavaScript (often referred to as simply JS) is a multi-paradigm language supporting event-driven, functional, and object-oriented styles. By itself, it does not include any I/O, storage, or networking, but instead borrows it from the host environment. It uses APIs for text, arrays, dates, regex, and the DOM. Although it initially started off as an embedded engine in web browsers on the client-side, it is now also found on the server-side. Every major web browser has an in-built JavaScript engine for executing JS code.
In this article, we will tell you some basic features of the language. For a more detailed explanation, we strongly suggest a JavaScript course.
Language Features
Basic features of JavaScriptDynamic typing
Similar to other scripting languages, types can be dynamically changed in JS. The type is associated with a value rather than an expression - a variable that is assigned to a Number might be reassigned to a String.
Form checks and calculations
JS is very good with form validation. As a client-side scripting tool, JS checks if the user has left a form field blank, or has entered an incorrect value, before sending the page to the server. It can also perform basic calculations on the client-side browser, rather than having the server allocate time for these simple calculations.
Thin or thick client
In the client-server architecture, a thin client is functionally light on processes. This means that a lot of the processing is done on the server. JS provides a lot of control to the browser (clients) rather than being completely dependent on the web-server. It can even provide additional functionalities to browsers to navigate network traffic via load balancing.
Platform independence
JS is an interpreted language, and so it does not need a compiler to compile it into machine code. It is readily interpreted by browsers and can run on any platform like Windows, Mac, Linux, etc.
Date and time handling
JS has built-in functions to get Date and Time values, unlike other programming languages. Methods like getHours(), getMinutes(), getDate() and many others are readily available in the library.
Dynamic code generation
HTML can be dynamically generated using JS on certain system events. For example, JS supports a whole lot of events for handling the Mouse – onClick, onMouseMove, onMouseover are some of the many examples. When the event takes place, JS could execute code to add text, links or images.
Browser and OS Detection
As JS is nearly universally installed on different platforms, it becomes necessary at times to get the Browser Type and the OS Type information about the machine that is making a web request. JS is capable of getting these values, so a programmer can write different code to run on different browsers and OSs if need be.
Replacement for Var
The var keyword (for variable) is not really a needed keyword in JS. But the variable that is being declared, without a var, is available in the global scope. That means it can be accessed anywhere in the program. To restrict this, JS has let and const as replacements, which are accessible only in blocked scope, not in the global scope. So if a variable is declared inside a function, its scope remains within that function using let and const.
Arrows
Arrow functions are used to reduce lines of code. Their syntax is () =>, where the keyword function is omitted. The parentheses are used to pass arguments to the function if there are any. It is important in general to reduce the lines of code in web programming since JS requests must make their way to a remote web server.
Function default parameters
If a function requires parameters to be passed to it, and you call that function without a parameter in your code, then the default value of that parameter is set to undefined. With default parameters, you can set the value of the parameter while defining the function itself.
Conclusion
The features of JavaScript outlined in this article are just of a few of the many features available and are meant to help initiate you to the language. JS is not very complicated to learn and is very popular for web scripting. Get started with client-side programming, before jumping into the server-side.The extensive documentation and support online will also make your life easier.
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