Frequently Asked JavaScript Questions and Answers for Freshers and Experienced

How do I get JavaScript?

Actually, you don’t need to get javascript. It’s already built-in all the browser’s engine. In order to get JavaScript, you would need to enable it in your web browser. Please make sure that you are currently using an up to date version of the web browser.
Enable JavaScript in your Google Chrome
1.Open Chrome on your computer.
2.click Settings at the top right.
3.click Advanced found at the bottom.
click Site settings under “Privacy and security”.
5.Find JavaScript and click it.
6.Find ‘Allowed’ and turn it on.
Enable JavaScript in Safari
1.If you’re using Safari on macOS. Click on Safari menu and select “Preferences”, alternatively, you can press Command+ if you are a Safari user on Windows.
2.In the “Preferences” window simply select the “Security” tab. In the “Security” section tab “Web content” select the “Enable JavaScript” box.
Close the Preferences popup window and refresh your webpage.
Opera Users
Click the Opera icon “Menu” and then select Settings.
Click “Websites” and then select the recommended option”Allow all sites to run JavaScript”
Click on the Reload/Refresh button of your web browser to refresh the web page.
Enable JavaScript in Mozilla Firefox
1.From the address bar, type in about: config and Enter.
2.Click the button “I’ll be careful, I promise” if you see a warning message.
3.Using the search box, search for javascript.enabled option
4.Switch the “javascript.enabled” preference to change its value from “false” to “true”.
5.Click the “Reload current page” button of your web browser to reload the page.
Enable JavaScript in Internet Explorer
1.From the web browser menu select “Tools” icon and click “Internet Options”.
2.Once you are in the “Internet Options” window click the “Security” tab.
3.On the “Security” tab select the “Custom level…” button and click it.
4.If the dialogue window “Security Settings Internet Zone” shows up, search for the “Scripting” section.
5.In the “Active Scripting” select “Enable”.
6.When the “Warning!” window shows up asking if you want to change the settings, select “Yes”.
7.In the window “Internet Options” select the “OK” button to simply close it.
8.Find and click the “Refresh” button of your web browser to reload the page.

Where can I download JavaScript?

You already have JavaScript if you have a browser. It is already built-in as similar to CSS. In addition, the majority of the browsers have this Developer Tools section that comes with a JavaScript Console that has the role of being one of the tools. All that you need can be found right on your computer.
You would also require a text editor, this would benefit from one that acknowledges code and has a feature syntax highlighting, an example is the Notepad++. There is a lot to choose from, although experts would propose this one since it is not difficult to utilize and an acceptable replacement for Notepad as the default editor for text on your computer.
Set a TXT type of files to open in your Notepad++, same goes with CSS and JS. In addition, these files could simply be selected to open it in the text editor. Notepad++ also has a free version that is completely up to the task for almost anything you do in CSS, HTML, PHP, JavaScript and other languages that it knows. As time passes by, you might transition to something more advanced. That advancement is lost on beginners.

Is JavaScript Free?

The JavaScript language as a format is free to use for everyone, and the use of JavaScript in a website is not that actually bad. However, it can be bad if the JavaScript program is not free to sue. Take note that when the website transfers a program to the user, it is not sufficient for the program to be put down in an unencumbered and documented language, that program should also be free. “Transmits only free of charge programs to the user” is mandatory to be part of the criterion for an honest and ethical website.

Comments in JavaScript with examples

JavaScript comments are considered hints that you as a programmer can put in addition to make your code easier to read and comprehend. The comments are ignored completely by JavaScript engines. JavaScript comments could also be utilized to avoid execution when testing other codes.
The JavaScript comment feature simplifies the production of readable code. They are also easy to write and recognize: usually, a JavaScript comment block or the multi-line comment starts with */ , while the single line comment will start with //. Multi-line comments usually are used more often for documentations that are formal.
Single-Line Comments example:
name = “Jill”;
// The Name
console.log(“Hello ” + name);
Here, // The name is a comment.
You can also use a single line comment just like this:
name = “Rose”;
console.log(“Hi” + name); // The name
Multi-line Comments
In Javascript, any of the text between /* and */ is considered a multi-line comment. For example,
/* The following program has the description of a game called PacMan.
Pac-Man is a Japanese based video game franchise published, owned and developed by Bandai Namco Entertainment.
Since the rest of the description will be used to introduce the background of the game, the sample comment above is one example where you can use a multi-line comment.

How do JavaScript engines work?

A JavaScript engine that is also limited contains a baseline compiler whose responsibility is to carry out the compilation of the code in the method of intermediate representation. In other words, this is called byte code which then provides the byte code to the translator.
In addition, the interpreter gets hold of this byte code and then does the conversion into a machine code. After that, the machine code will run further with this code on the hardware of your machine.
It is very alike to the operation of Java but the byte code’s generation is done by a programmer and the byte code has been divided universally, not the source code.
These are three of the popular projects implementing a JavaScript engine:
V8 — developed by Google, open-source, written in C++
Rhino — open-source, managed by the Mozilla Foundation, developed totally in Java
JavaScriptCore — marketed as Nitro and this was developed by Apple specifically for Safari, open-source.
SpiderMonkey — also known as the first JavaScript engine, back in the days this powered the Netscape Navigator, and today it powers Firefox
KJS — KDE’s originally developed engine by Harri Porten specifically for the web browser of KDE project’s Konqueror.

What makes JavaScript unique?

Modern JavaScript is considered a “safe” programming language. JavaScript does not give low-level access to CPU or memory, because it was created initially for browsers that do not usually require it.
The capabilities of JavaScript greatly depend on the current environment it is operating in. For example, Node.js supports functions that permit JavaScript to perform network requests, write/read arbitrary files, etc.
In-browser JavaScript could do anything related to interaction with the user, webpage manipulation, and the webserver.
In addition, in-browser JavaScript is able to:
1.Add a new HTML to a page, update the existing content, improve styles.
2.Respond to user actions, pointer movements, run on mouse clicks and key presses.
3.Send numerous requests over the network towards remote servers, upload and download files.
4.Set and get cookies, show messages, ask questions to the visitor
5.Remembering the data of the client-side ( known as “local storage”).
There are also some interesting things found in the Javascript world.
Number as object type
In other programming languages, usually, there is a difference of type for float and integer, but Javascript knows only one object type for numbers so there is no such thing in JavaScript as an integer that can be found from Mozilla docs.
There is an “undefined’ value found on Javascript which is known as a value of type undefined that specifies an uninitialized value. Normally in other languages, the value (uninitialized) is similar to “null” or “nil”. However, Javascript has both null and undefined.
Callback functions
Functions are known as first-class objects in Javascript, user can easily pass a function as an argument towards another function and later on execute that passed-in function, or also return it to be even executed for later. This is the core of using the function of callback in JavaScript. These special functions are likely the widely and most used technique in JavaScript in functional programming and could create heaven or hell in your code if you are to use it wrongly. That is why it is often heard as a callback hell occurrence in the Javascript world.
Competing in server side and front end
Only Javascript can defeat the reign of intense popularity of programming language for both server side and front end developers. This is because Javascript contains NodeJs which is considered to be “JavaScript environment based on V8 Event-driven I/O server-side”. This could probably be the most captivating and one of a kind aspect of Javascript.