JavaScript Online Practice Test 2025

JavaScript (/dvskrpt/), also known as JS, is a programming language that adheres to the ECMAScript specification. JavaScript is a high-level programming language that is often compiled just-in-time and is multi-paradigm. Curly-bracket syntax, dynamic typing, prototype-based object-orientation, and first-class functions are all included.

To enable JavaScript in Internet Explorer 8, go to the Tools menu, select Internet Options, and then select the Security tab. Select the Internet tab. Then select Custom Level. In the Scripting section of the Security Settings – Internet Zone dialog box, click Enable for Active Scripting.

JavaScript is a scripting language that is often used to create web pages. It enables us to add dynamic behavior to the homepage as well as special effects. It is primarily used on websites for validation purposes.

JavaScript (JS) is a type of scripting language that is mostly used on the internet. It is widely seen in HTML code and is used to enhance HTML pages. JavaScript is a scripting language that is interpreted.

Open the Settings app on your iPhone. On the Home Screen, it’s a grey set of gears. Scroll to the bottom of the page and select Safari. About halfway down the Settings page, you’ll see this option. Scroll to the bottom of the page and select Advanced. It can be found near the bottom of the screen. Right-click the white JavaScript switch. It will change color to green.

Yes, JavaScript is an interpreted programming language that is lightweight.

Locate the “browser” symbol in the “Apps” listing menu on your phone, and then click it.

• Tap the Menu icon when the browser window appears. You can also do this by pressing the Menu button on your Android device.
• Select “Settings” from the Menu Icon.
• Choose the “Advanced” section under the “Settings” tab and select “Sites and downloads.”
• To allow JavaScript on your Android phone or tablet, scroll down to “Allow JavaScript” and toggle on the switch beside it.
• To save the settings, simply exit the page.

The majority of programmers agree that learning JavaScript takes six to nine months to master. Even then, you’ll have to spend years learning new talents and refining your knowledge.

Go to Manage Add-ons from the Tools menu (the gear symbol at the top right of the browser window). A Show: menu will appear in the middle of the left-hand side of the window. Select All Add-ons from the Show menu. To find any Java add-ons, scroll down to the right. Select Disable from the menu by right-clicking.

JavaScript is one of the most widely used programming languages in the world, primarily for adding automation, animations, and interaction to Web pages. JavaScript is used by web developers to automate simple operations as well as create complex Web sites that behave like desktop software programs. JavaScript is also utilized in software, servers, and embedded hardware controllers, in addition to the Web.

Open a text editor that is easy. Create an HTML block and start typing. In the HTML head, place a script tag. A JavaScript function can be used to launch other JavaScript scripts. Save As… (Windows) or Save As… (Mac) In the format drop-down menu, select.html. Click Save after giving your document a name. To open your file in a browser, double-click it.

The script> tag can be used to link JavaScript to HTML. When adding JS to HTML, you may encounter one of three circumstances. It’s possible that you have a-

• External JavaScript – The only difference between linking an external JavaScript file and linking a local JS file is that the file is on a distant server. As a result, you must include the JS file’s URL.
• Local JavaScript – You can use the src attribute to the link if you have a JS file in your local project folder. You must specify the Js file’s local path in order to link it.
• Inline JavaScript code – Simply add a pair of HTML Script>/Script> tags and create or put your JavaScript code in between the tags.

JavaScript is a scripting language that is used to create interactive web pages. It has the ability to add dynamic text to HTML pages. The browser’s language is referred to as JavaScript. JavaScript (JS) is not connected to or similar to Java, which is an object-oriented programming language with a virtual machine platform that allows you to develop compiled applications that run on almost any platform. “Write Once, Run Anywhere” was the promise made by Java.

Follow the steps below to disable JavaScript in the Tor Browser:

1. Double-click the tor browser’s icon to launch it.
2. Now look for the menu sign, which is usually towards the top-right corner of the browser, and click it:
3. When the menu appears, look for “Options” in the following options and click it to access the Tor browser preferences.
4. When the settings tab appears, select “Settings and Privacy” from the left-hand menu and look for the Security option among the options.
5. To disable JavaScript, select “Safest” from the drop-down menu and exit the settings tab.

The Tor browser also includes an alternate method for disabling JavaScript, which is to utilize the “NoScript” option to turn off all scripts in the browser.

Unlike many other languages, JavaScript does not have a simple Print command. However, you can show text in a variety of ways, including within an HTML document, an alert window, or the console. You can also print from a printer with JavaScript. In the body of your HTML document, Type <p id=.

JavaScript is case sensitive.

In JavaScript, there are two methods for commenting out the code:

• Single line comment – A single-line comment is one that will only produce one line of text. Add double forward slashes // at the beginning of the JavaScript code to do this. JavaScript ignores any code between // and the end of the statement.
• Multiple line comment – When you want to comment out a big line of code or add extra information so that others understand what your code does or why it’s used, you use a multiple-line comment.

When you enable JavaScript in Internet Explorer, you’ll be able to see websites and web pages created with this programming language. JavaScript can be turned on in Internet Explorer’s Tools menu under Internet Options.

1. Start an Internet Explorer session on your computer or device.
2. Select “Internet Options” from the “Tools” menu at the top of your session. The Internet Options window will appear on-screen.
3. Select the “Security” tab from the drop-down menu.
4. Select “Internet” from the drop-down menu.
5. Select “Custom Level” from the drop-down menu.
6. Go to “Security Settings – Internet Zone” under the “Security Settings – Internet Zone” section.
7. Scroll to the “Scripting” section at the bottom of the page.
8. Select “Enable” next to the “Active Scripting” option.
9. In Internet Options, click “OK,” or select the option that stores your selections.
10. In your Internet Explorer session, click the “Back” button.
11. In your browser, press the “Refresh” button. In the future, Internet Explorer will refresh and begin to run JavaScript.

 Use HTML script tag Creating an HTML file is the simplest way to run JavaScript in VS Code. This method is simple because seeing JavaScript results requires only VS Code and a browser of your choosing. Here’s how you’ll go about it:

1. In VS Code, create an HTML file and add the script tags to it. Within the script tags, you can write JavaScript code.
2. After saving your changes, open the HTML file in your browser.
3. Right-click the mouse and select the Inspect option to launch the inspect window in the browser. You may also open it by pressing Ctrl + Shift + I on a Windows computer or Cmd + Option + I on a Mac computer.
4. The JavaScript outputs can be seen by clicking the Console tab in the Inspect Window.

The main disadvantage of this method is that you will be switching back and forth between a browser and VS Code windows all the time. Unless you’re working with tiny windows or two monitor screens, this will be a minor annoyance.

We must use the script tag script type = “text/javascript” src = “function.js”> to include our JavaScript file in the HTML document, and we must supply the path to our JavaScript file in the “src” property.

In JavaScript, here’s how to write a function.

• Use the keyword function, followed by the function’s name.
• Open and close parenthesis after the function name.
• Curly braces should be opened and closed after parenthesis.
• Write your lines of code inside curly braces.

We may also use an external JavaScript file attached to our HTML content to call JavaScript functions. To do so, we must first construct a JavaScript file in which we will define our function and save it with the (.Js) suffix.

After we’ve produced the JavaScript file, we’ll need to develop a simple HTML document. We must use the script tag script type = “text/javascript” src = “function.js”> to include our JavaScript file in the HTML document, and we must supply the path to our JavaScript file in the “src” property. We can create a button and use the “onclick” property to call the function after attaching the external JavaScript code to the HTML document.

Either an array initializer (array literal) or the Array constructor can be used to generate an array. The array literal (array initializer) syntax is straightforward: a comma-separated list of values enclosed in square brackets.

• Step 1: Open your Web browser and go to the Java website (see the References section of this article for the link).
• Step 2: Find the section for your operating system by scrolling down in the window.
• Step 3: To download JavaScript, click the file name next to the red arrow. This will start the download process.
• Step 4: To install the latest version of JavaScript, double-click on the downloaded file and follow the on-screen instructions.

Select Safari -> Preferences from the menu toolbar to enable or disable Java in the Safari browser. Window click on the Security icon in the settings. If you want Java enabled, tick the Enable Java checkbox; if you want it removed, uncheck it. Close the settings window to save your changes.

JavaScript allows you to open a file so that the user can save it to their computer or simply read it and close it. This type of programming is typically used to open a file when a user picks a file from an HTML page’s “Browse” button. The selected file is delivered to the JavaScript code, which uses the “window.location” function to open it.

• 1st step To open an HTML file, right-click it and select Open With. Double-click the desired JavaScript editor after clicking “Open With.”
• 2nd Step Make a JavaScript function for it. The following function opens the file that the user has selected: function openfile(file) { window.location = “file:///” + file; }
• 3rd step Add the function to the web page’s “Browse” button. In the tag’s code, type the following: onclick=”openfile(this.value)”
• 4th step Save the file to your computer and open it with your default browser. Select a file on your computer and open it with the code.

Reversing a string is one of the most typical programming tasks, yet because the JavaScript String object lacks the reverse() method, you’ll have to come up with a solution.

There are two simple methods for reversing a string:

1. Call the Array.reverse() method after converting the string to an array. To reverse a string, you must first convert it to an array using the String.split() method The String object has a built-in method called split() that allows you to split a string into several array members. If you give the method an empty string (“”) as an argument, it will return an array with each character as its own entry.
2. Create a new reversed string from the original string using a for loop statement.

Use the string length – 1 as the initial expression value and decrement the loop value in each iteration as long as it’s more than or equal to zero to reverse a string using a for loop: Then, using the index, construct a new empty string and append each character from the original string backwards.

With the help of a tool called NodeJs, you can run JavaScript in the terminal. NodeJs is a free and open-source run-time environment that enables you to create JavaScript command-line tools and server-side scripts without having to use a browser.

Brendan Eich, while working at Netscape Communications in 1995, created JavaScript. Java, Scheme, and Self

To activate and enable JavaScript in iOS on the iPhone and iPad, follow these instructions.

iOS Safari

• On the iPhone home screen, tap the Settings application/icon.
• On the next screen, choose Safari.
• Select Advanced from the drop-down menu near the bottom of the next screen.
• To make the JavaScript toggle highlight green, move it to the right.

There are a few options.

• To sort an array in ascending order, simply call THEARRAY.sort();.
• To sort an array in descending order, use THEARRAY.sort().reverse().
• To sort an array of numbers in ascending order, use THEARRAY.sort(function(a, b){ return a-b; });
• To sort an array of numbers in descending order, use THEARRAY.sort(function(a, b){ return b-a; });

That’s all there is to simple sorting.

JavaScript is only asynchronous in that it can make Ajax calls, for example. The Ajax call will pause, allowing other code to continue until the call returns (successfully or unsuccessfully), at which point the callback will run synchronously. At this point, no other code will be running.

The front-end is sometimes known as the ” client-side ” of an application, as opposed to the backend, which is the ” server-side “. Languages like Java, Ruby, Python, PHP,.Net, and others are necessary for backend web development. HTML, CSS, and JavaScript are the most common frontend languages.

The JavaScript framework is a JavaScript application framework that allows developers to control and leverage capacities to their advantage. That’s how JavaScript frameworks work, and that’s how projects progress. You can write all of the code for every area of your site without any prior preparation.

VanillaJS is a phrase for JavaScript without a library or framework. It’s sometimes jokingly referred to as a library by people who are accused of blindly employing many frameworks, particularly jQuery. Some people have gone as far as to release this library, usually with a comment-only or empty js file.

The first step is to construct an object in JavaScript using the Date() function: Then, to get the current date in the “m-d-y” format, run the script below. You have the option to alter the format.

• getDate() — Provides the month day values 1-31.
• getMonth() – Provides the current month as a list of 0-11 numbers (0 for Jan and 11 for Dec). To get the result, you should add +1.
• getFullYear() – Provides the year that is currently in use.

JavaScript is not a compiled language, but rather an interpreted language.

Yes, learning the fundamentals of JavaScript is simple. However, completely comprehending programming ideas, interoperability with other languages, and all related technologies can take years of study.

One of the main advantages of JavaScript for individuals who want to learn to program is that it is completely free. To get started, you don’t need to pay anything.

Python is easier than JavaScript. Python is frequently the first programming language that people learn, especially if they have never programmed before. Python code is well-known for being more readable and easier to understand (and write).

Symbols ( [] ;, ()! are scattered throughout the usual JavaScript program. =) and is absolutely packed of words you’ve never heard before (var, null, else if).

A closure is a function that has been bundled together (enclosed) with references to its surroundings (the lexical environment). In other words, a closure allows an inner function to access the scope of an outside function. Closures are formed every time a function is created in JavaScript, during function creation time.

Constants, like variables declared with the let keyword, are block-scoped. A constant’s value cannot be modified by reassignment (that is, via the assignment operator), and it cannot be redeclared (i.e. through a variable declaration). A constant that is an object or an array, on the other hand, can have its properties or items altered or removed.

Hoisting is the default behavior in JavaScript, which moves all declarations to the top of the scope before code execution. It essentially gives us the advantage that no matter where functions and variables are declared, they will be relocated to the top of their scope, whether global or local.

It is supported by almost all browsers, including IE9+, the Object.keys() method is likely the best approach to check if an object is empty. It produces an array containing the names of the properties of the specified object.

Use the parseFloat() function to take a text and convert it to a floating point number. parseFloat expects a string or a string expression as a parameter. The number whose decimal representation was contained in that string is returned by parseFloat (or the number found at the beginning of the string).

The function keyword is used to define or declare functions.

The function keyword is followed by the function’s name in the declaration. The same restrictions apply to function names as they do to variables: they can contain letters, numbers, underscores, and dollar signs, and they’re usually written in camel case. A set of parenthesis follows the name, which can be used for optional parameters. The function’s code is enclosed in curly brackets, similar to a for or an if statement.

The document.getElementById() method and the button disabled property, button.disabled, can be used to disable the button.

Under the “Browsing” settings. Remove the check from the “Disable Script Debugging” option. “Display a notification about every script error.” should be unchecked. To save your settings, go to the bottom of the “Internet Options” box and click the “Apply” button.

The question of whether JavaScript is open source is, however, slightly off the target. JavaScript is a computer language, whereas “open source” refers to programs. It’s an open standard, and in some ways it’s a near approximation – at least in the sense that it’s not a “propriety” language owned and controlled by a single firm.

No. JavaScript is a scripting language based on the Java programming language. In WebTechnologies, JavaScript is largely utilized for client-side validations (like html, php etc.).

A number of statements in JavaScript influence the program’s flow. There are a few:

• conditionals (if-else, switch) that, based on the value of an expression, take different actions
• loops (while, do-while, for, for-in, for-of),that repeatedly executes other statements,
• jumps (break, continue,designated phrase) that causes the program to go to a different section.

JavaScript libraries are a collection of universally accessible pre-written JS code files that speed up the building of websites and web-based applications.

Although JavaScript on the iPhone can be used in a variety of useful ways, it is also used by a number of people to hijack our browser. Injecting the marquis search spam into the Safari browser, for example.

JavaScript does not have classes in the same way that other Object-Oriented languages such as Java or Ruby do. However, in ES6, the class keyword was introduced as a syntax for object construction.

In Java, this is a traditional method for comparing two java.util.Date objects. If the dates are equal, the return result is 0. If Date is after the date parameter, the return result is larger than 0. If Date comes before the date input, the return result is less than 0.

When it comes to string concatenation in JavaScript, you have a lot of alternatives. You can make use of:

• The + operator.
• Template literals.
• String’s built-in concat() function.
• Array’s built-in join() function.

Another method to learn JavaScript quickly is to put it to use. Active practice entails spending more time developing code rather than simply watching or reading tutorials. Every day, try to write code for at least 30 minutes to an hour. You will increase your JavaScript knowledge more quickly if you write code on a regular basis and practice what you’ve learnt.

Choosing an Easy-to-Use JS Library for Your Discord Bot is the Most Popular Way to Make a Discord Bot. Making a Discord Bot Application and Getting a Token The first step is to create your bot application and obtain a custom token allocated to it.The Next Steps in Discord Bot Development Using JavaScript and Node.js

To remove elements from an existing Array, JavaScript provides numerous methods. The pop(), shift(), and splice() procedures can be used to eliminate items from the end of an array, the beginning of an array, or the middle of an array.

The “Write Less, Do More” JavaScript library is jQuery. It is not a programming language, but rather a tool for condensing the writing of typical JavaScript jobs. jQuery also has the advantage of being cross-browser compatible, which means that the output of your code will look exactly as you meant it to in any modern browser.

A Regular Expression (RegEx) is a JavaScript object that describes a string of characters that defines a search pattern.

JavaScript is a scripting language for creating dynamically updated material, controlling multimedia, animating pictures, and pretty much anything else. (Okay, not everything, but it’s amazing what a few lines of JavaScript code can accomplish.)

JavaScript is a great language for creating online apps that are object-oriented. Because it enables inheritance through prototyping as well as properties and methods, it may support OOP. Because they are so used to the class style of C# and Java, many developers dismiss JS as a suitable OOP language.

JavaScript has never been known to be safe in a browser. To achieve nefarious purposes, malicious code developers are continually looking for new ways to abuse how each engine operates as well as its available JavaScript features. JavaScript was quite risky in the browser for the first few years.

JavaScript is a single-threaded and non-blocking language. The term “single threaded” refers to the fact that only one statement is executed at a time. A memory heap and a call stack are used by the JavaScript engine. The job of the call stack is to fill in the instructions and pop them as they are executed.

In JavaScript, the keyword void is used as a unary operator that appears before its single operand, which can be of any type. This operator is used to specify an expression that will be evaluated but will not yield a value.

Node.js is a backend platform that lets developers use JavaScript on the server side of their apps. It may be used to collect data from sensors and regulate your home thermostat, among other things. Node, on the other hand, has modules and packages designed exclusively for front-end development.

The JavaScript console log function is mostly used for debugging purposes because it causes JavaScript to print its output to the console. Right-click on the page and select Inspect, then click Console to view the browser console.

Unlike the var keyword, which declares a variable globally or locally to an entire function regardless of block scope, the let keyword allows you to declare variables that are limited to the scope of the block statement or expression on which it is used. Another distinction between var and let is that the latter is only initialized to a value when it is evaluated by a parser.

Node. js is a server-side application framework based on JavaScript. In its most basic version, it allows you to run small JavaScript programs directly from the command line, bypassing the need for a browser.