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In JavaScript, objects are a fundamental data structure that allows you to store and manipulate data. Sometimes, you may need to loop through or enumerate an object to access its properties or perform some operations on them. In this article, we will discuss how to loop through or enumerate JavaScript objects.

The Concept

In JavaScript, objects are collections of properties, where each property is a key-value pair. To loop through or enumerate an object, you need to access its properties and perform some operations on them. There are several ways to loop through or enumerate an object in JavaScript, including:

for…in loop: This loop is specifically designed for iterating over object properties. It iterates over all enumerable properties of an object and its prototype chain.

Object.keys() method: This method returns an array of a given object’s own enumerable property names.

Object.values() method: This method returns an array of a given object’s own enumerable property values.

Object.entries() method: This method returns an array of a given object’s own enumerable property [key, value] pairs.

Usage in JavaScript 1. chúng tôi loop

The chúng tôi loop is the most common way to loop through or enumerate an object in JavaScript. Here’s an example:

const person = { name: 'John', age: 30, gender: 'male' }; for (let key in person) { console.log(key + ': ' + person[key]); }

Output:

name: John age: 30 gender: male

In this example, we create an object person with three properties: name, age, and gender. We then use a chúng tôi loop to iterate over the object’s properties and log them to the console.

2. Object.keys() method

The Object.keys() method returns an array of a given object’s own enumerable property names. Here’s an example:

const person = { name: 'John', age: 30, gender: 'male' }; const keys = Object.keys(person); console.log(keys);

Output:

["name", "age", "gender"]

In this example, we create an object person with three properties: name, age, and gender. We then use the Object.keys() method to get an array of the object’s property names and log them to the console.

3. Object.values() method

The Object.values() method returns an array of a given object’s own enumerable property values. Here’s an example:

const person = { name: 'John', age: 30, gender: 'male' }; const values = Object.values(person); console.log(values);

Output:

["John", 30, "male"]

In this example, we create an object person with three properties: name, age, and gender. We then use the Object.values() method to get an array of the object’s property values and log them to the console.

4. Object.entries() method

The Object.entries() method returns an array of a given object’s own enumerable property [key, value] pairs. Here’s an example:

const person = { name: 'John', age: 30, gender: 'male' }; const entries = Object.entries(person); console.log(entries);

Output:

[["name", "John"], ["age", 30], ["gender", "male"]]

In this example, we create an object person with three properties: name, age, and gender. We then use the Object.entries() method to get an array of the object’s property [key, value] pairs and log them to the console.

Conclusion

In JavaScript, objects are a fundamental data structure that allows you to store and manipulate data. To loop through or enumerate an object, you can use the chúng tôi loop or the Object.keys(), Object.values(), and Object.entries() methods. These methods provide different ways to access an object’s properties and perform operations on them. By understanding how to loop through or enumerate JavaScript objects, you can write more efficient and effective code.

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Learn How To Create Some Objects?

Introduction to Inkscape animation

Inkscape animation stands for creating frames for animating some objects of any illustration work that means in animation we have the number of frames which change within a fraction of time and give motion to animating object so here in the Inkscape we can create these frames by making changes in the different part of the object or different object of the illustration which we want to animate and after creating them we should need a software which converts that frames in animation that means you can make Gif by combining these frames. So let us find how we can create and save frames of an animation in Inkscape.

Now let us create some objects in which we will make variations for having frames of animation. I will make a background first. So for making it, I will take the Rectangle tool from the tool panel or press the F4 functional key of the keyboard as the shortcut key of this tool. I am drawing a freehand rectangle you can take specific dimensions for it. I will choose the blue color as my background.

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Now take Ellipse or Circle tool from the tool panel or press F5 shortcut key of the keyboard then draw a circle and make a moon-like shape like this. I use the Node editing tool for editing nodes of this circle.

This is part of the hand and I want to make them as one part because I used two different rectangles for making it so for making them one part I will select them.

I have made part of this object separately like this so that I can animate them by moving them in the desired direction. During creating any object which you want to animate make sure you have separated parts of that object which parts you want to include in animation.

Now I will take the Circle tool again and make this type of circle for giving extra effect to my animation. After making these circles select all circles and group them.

Now select this circle and make a copy of it. For making a copy of it press the Ctrl + d button of the keyboard as short cut key. I will make two copies of it and place them like this by moving them with the selection tool.

Choose a location where you want to save your png of this illustration. I will suggest making a folder for having a collection of all frames of this illustration for using them in animation. Name your illustration according to you just add a numbering letter so that you can identify the sequence of frames in the right way. I will name my work as 1.

Now you can see my work is saved at my desired location.

Now I will rotate this hand of the moon so that I will move in my animation. I will move the rotation center of the hand at the joint of the hand to the body because I want to rotate it from here. So make sure you place the rotation center point at that place from where you want to rotate any part of the object.

Now rotate another hand of it in the same way in the other direction.

I will animate the eyes of the moon also and for doing this I will rotate both of the eyes a little bit in opposite directions one by one.

In the next step, I will move the upper lip in the upper direction a little bit and the lower lip in the lower direction one by one.

And move slightly these circles in a forwarding direction one by one.

Now I will select all objects of this illustration again with the background then save it as 2 in the same way as we follow for 1 png frame.

In the next frame, I will only move circles in a forwarding direction and export it as a 3 png file.

Make changes in each frame according to your choice and save them one by one in sequence. I saved 5 frames here but we need more than it for having motion in our animation.

Now open it in the image viewer application and change each frame by pressing the forward button of the viewer application in speed and you can see your animation here. If you satisfy with this animation then take all frames of animation into the software through which you can make gifs with this frame. You can use GIMP for having gif from these frames.

I discussed all steps here through which you can create frames for an effective animation.

Conclusion

I think you got very informative knowledge from this article for creating the animation of your desired objects of illustration. You can also use vector objects which you have been taken from the internet for this purpose just make sure you have separated parts of that object so that you can really move them for having natural animation.

How To Fix Configuring Roblox Loop Error

ROBLOX users may find that their screen is stuck on Configuring ROBLOX or that it goes in a loop. If you see this error, then this post will be able to help you fix the problem.

Roblox is a popular platform that lets the users create and play games. It has gained popularity among gamers for this unique reason. They can create the game they want to play and build on their instincts and creativity easily with Roblox. There are some users who are reporting that they are seeing Roblox configuring loop error while trying to configure the app on their PC. A bad internet connection, the over-protective antivirus, geo-blocks, etc might be the cause of this loop error on Roblox. In this guide, we have a few solutions that can help you fix the error.

What does it mean when Roblox is configuring?

During the installation of Roblox on your PC, it shows configuring on screen. Roblox is actually settings itself up to your PC and the configuration for a better experience. It copies the necessary files and components onto your PC for the Roblox to run smoothly.

How to fix Configuring ROBLOX Loop Error

Roblox stuck in Configuring ROBLOX screen can be fixed in the following ways:

Turn off antivirus

Check your internet connection

Use a VPN

Clear the Roblox cache

Reinstall Roblox application

Let’s get into the details of each method and fix the loop error on Roblox.

1] Turn off antivirus

Roblox configuring loop error might have been caused by the antivirus you have installed on your PC. It might be acting against Roblox program and blocking its configuration. Turn off antivirus for the time being and try configuring it again.

2] Check your internet connection

A bad internet connection can play its part in creating issues on Roblox. Roblox is a platform that relies on data transfers between your PC and its servers. You need to have a good internet connection with good speeds. Also, check if your internet connection is working fine without any trouble.

3] Use a VPN

Roblox’s configuration loop error might have occurred due to geo-blocks that are in-place in your region. Use a VPN and try configuring Roblox. Even if your nearest server is down, using a VPN can help you connect to another server of the location you choose on the VPN.

4] Clear the Roblox cache

To clear the Roblox cache, press Win + R and type %Temp%Roblox and hit Enter. Now press Ctrl + A and delete everything in the folder.

5] Reinstall Roblox application

Uninstall Roblox application from your PC and clear its cache and data. After that, reinstall Roblox and try configuring Roblox again. Remember, you must clear the cache and data before installing it again on your PC.

This is how you can fix Roblox stuck in configuring (loop error).

How do you fix a stuck Roblox update?

If the Roblox update is stuck, try installing the update by downloading it from the official site, clear app cache, check your internet connection, turn off antivirus until the update is installed completely.

Related Read: How to fix An error occurred while starting Roblox.

How To Create The Loop Structure In Less

Overview

Loops make our code clean and help to run the same lines of code multiple times. This makes a code to not to write the same lines of code multiple times. So to style the multiple containers and objects the same can be done by writing a line of code and repeating the same styling property several times. So to come up from this problem, Leaner Style Sheets (LESS) provides a looping facility by using which we can make our code readability easy and can save the developer time of developers in writing numbers of lines of styling property code.

Syntax

The syntax to use the loop in Leaner Style Sheets (LESS) is −

functionName

(

@variableName

)

when

(

terminationCondition

)

{

selector

{

font

size

(

18px

@variable

);

color

green

}

functionName

(

decrement

increment

);

}

functionName − The function name can be user-defined as per the developers choice.

variableName − The variable name can also be written by the developer. The variable name in the LESS preprocessor is written with the prefix “@” in it. Example: @name, @width, @height, @border etc.

selector − The selector inside the loop are the class, id and tag that are to be styled dynamically with the loop.

Increment/decrement − These are the conditional properties which depend upon the situation that the developer wants to perform the task.

TerminationCondition − It is the condition at which the loop stops. Suppose the termination condition is set to variable greater than 0 and variable gets decremented so when the variable value will be equals to or smaller than 0 the loop will be terminated.

Algorithm

Step 1 − Create a HTML boilerplate in any text editor. Add a few elements with class names.

Step 2 − Link the style sheet to the HTML page with the link as “ chúng tôi ”.

Step 3 − Create a “style.less” file in the same folder and create a loop using the above given syntax with the user defined function name, variable name.

Step 4 − Add the termination condition as the loop terminates when the variable value is smaller than 0

Step 5 − Now inherit the styling component to which we had to reflect the styling. If the class name is the same with a change in number then we can use the current variable value and concatenate it with the class name.

Step 6 − Decrement the current value of the variable. To take the loop to the termination condition. If this step is not followed then the loop will take the current value and will reflect the change only once.

.space@{variable} { font-size : (18px * @variable); color:green } .fsize(@variable – 1); }

Step 7 − When the loop ends, call the function and pass the value in it.

.fsize(3);

Step 8 − Open the terminal and reach the current folder in it using the “cd” command which changes the directory.

Step 9 − Use the following command to compile the less file.

Step 10 − Now the LESS file is compiled and converted to “ chúng tôi ”.

Step 11 − Output can be seen on the browser.

Example

In the given example, we have created a simple HTML page with few HTML div tags in it. In the chúng tôi file we have created a loop through which we have iterated the styling property which reflects the particular selected selector which is the class name. In the chúng tôi code given below a fsize() function is taken into consideration in which the variable is passed as parameter. In the loop we had used the recursive property which terminates when the value of the variable is smaller or equal to the 0.

.space3 { font-size: 54px; color: green; } .space2 { font-size: 36px; color: green; } .space1 { font-size: 18px; color: green; } .space@{variable} { font-size : (18px * @variable); color:green } .fsize(@variable – 1); } .fsize(3);

To reflect the styling to the main page we have to convert the chúng tôi to styling sheet to the chúng tôi because the chúng tôi sheet is linked with the index page. To convert it we should have a less compiler which will compile the given less file to css. Now open the terminal and reach the chúng tôi folder to use the less compiler command given below.

Using the above command the less file is compiled and converted into Cascading Style Sheet (CSS) which changes the styling of the page. The below chúng tôi code is the resultant of the above compiled less file which contains the loop.

The below image contains the output of the above example, which contains three div containers with text in it. so when in the less file the function is called the loop starts and it initializes the variable with value 3, when the style property style gets the value it calculates and changes the font size accordingly with the same color name. then the value of the variable gets decremented by 1 then the value of the variable sets to 2 and the same procedure goes on until the value of the variable is less then or equals to 0. when the value of the variable is equal to 0 the loop gets terminated and when compiled using the lessc compiler it reflects the changes to css page which reflects the styling to the main index page.

Conclusion

When the name of variable is given wrong in some part of the code, while compiling the code it gives an error. When we are calling the function outside the loop the feature in the LESS is called mixin. This is a great feature of LESS through which we can use the property of the one element with another. To run the above loop one must have the basic understanding of how the loop works and the understanding of recursion.

How To Handle A Python Exception Within A Loop?

The looping technique in Python transforms complex problems into simple ones. It allows us to change the flow of the program so that instead of writing the same code over and over, we can repeat it a limited number of times until a certain condition is satisfied. For example, if we need to display the first ten natural numbers, we can do it inside a loop that runs up to ten iterations rather than using the print command ten times.

Python offers three ways to loop a block of code in a program: using for loops, while loops and nested loops.

In this article, let us see how we can handle exceptions within these loops.

Handling Exception in While Loops

While loops run statements (code) continuously as long as the provided condition is TRUE. It initially examines the condition before proceeding with the instructions.

Syntax while condition: statements(code)

There are number of statements that are present inside the while loop. The condition could be anything we want it to be. When the condition fails (becomes false), the loop terminates and the execution proceeds to the next line of code.

Exception handling in while loop is very similar to the usual approach. The code containing the possibility of an exception is enclosed in a try block.

We have statements that are preceded by the keyword “except.” It is possible to make “customized” exceptions: The raise statement can be used to force the occurrence of a specific exception.

Example

Assume we wish to request an integer number from the user. It is accomplished by using the input() method. However, the default value of the input obtained from this method is a string; that we must convert to an integer. It is done using typecasting with (int).

Here, we shall raise a ValueError if the input given to the method is not a valid integer. The while loop will keep asking the user to enter a correct value every time a wrong type of input is given. Once the correct value is inputted, the loop is exited. This is demonstrated in the following example −

# The loops keeps executing until the value entered is an integer while True: try: n = int(input("Please Enter an Integer: ")) break except ValueError: print(" The Integer You entered is not valid! Please try again…") print("You successfully entered an Integer!") Output

As seen in the output below, the while loop keeps executing until the correct value is entered as an input.

Please Enter an Integer: g The Integer You entered is not valid! Please try again… Please Enter an Integer: h The Integer You entered is not valid! Please try again… Please Enter an Integer: 7 You successfully entered an Integer! Handling Exception in For Loops

In Python, the for loop iterates across a sequence (list, tuple, string) or other iterable objects. The process of iterating across a sequence is known as traversal.

for val in sequence: loop body

On each iteration, val is the variable that takes the value of the item in the sequence.

The loop is repeated until we reach the last item in the sequence. Indentation is used to separate the body of the for loop from the rest of the code.

Let’s check whether we can access an array index that is longer than the array’s length and handle the subsequent exception.

Example

In the following example, we are looping through a list containing the names of months using for loop. Names of these months are printed if they exist in the list; and once the loop exceeds the length of the given list, except block is executed and output is displayed accordingly.

array = ["Jan", "Feb", "Mar", "Apr"] for i in range(5): try: print("The element from the array present in index", i,"is", array[i]) except: print ("Index out of range") Output

The output for the program above is produced as follows −

The element from the array present in index 0 is Jan The element from the array present in index 1 is Feb The element from the array present in index 2 is Mar The element from the array present in index 3 is Apr Index out of range

How To Detect Mobile Browsers With Javascript

Mobile detection has always been a crucial aspect of app development. It is relevant both for apps, but also software and websites. There are countless reasons to check for mobile browser agents. Most importantly, the ability to render a unique user experience.

Sometimes you might just want a simple solution that does the job without any libraries. And in this article, I am gonna lay out for you a handful of JavaScript techniques for detecting mobile users. Let me know if I missed any!

navigator.userAgent

The holy grail of browser detection is the navigator.UserAgent property.

}

// an alternative structure to check individual matches if ( navigator.userAgent.match(/iPhone/i) ) { }

This is, of course, a very primitive way of doing it. It can easily be manipulated as the User-Agent property can be spoofed. But, you can still use it in various projects because it does the job. E.g. Landing pages or making a custom redirect to a mobile version.

How to display a warning message if the user uses an unsupported or outdated browser?

One way this property can be used is to check whether or not the user is using a specific version of a browser, and, if not – perform an action.

In this example, it’s a simple alert message:

var userAgent = navigator.userAgent; var browserVersion = userAgent.substring(userAgent.indexOf("Chrome") + 7); if (parseFloat(browserVersion) < 107) { alert("Your browser is outdated and not supported. Please upgrade to the latest version."); }

☰ What does the “+ 7” do?

In this case, the number 7 in the browserVersion string is used to specify the index at which to start extracting the substring from the userAgent string. The userAgent string is a property of the navigator object in JavaScript that contains information about the user’s browser, such as its name and version number.

In this case, the code is using the indexOf method to find the index of the first occurrence of the string "Chrome" within the userAgent string. This method returns the index of the string’s first character that it is searching for. The number 7 is added to this value, which means that the substring extraction will start at the 8th character of the userAgent string (since array indexes in JavaScript start at 0). This allows the code to skip the first seven characters of the userAgent string (i.e. the characters “Chrome” plus the space after it) and start extracting the substring at the character immediately following the space.

How to redirect users to a mobile version of the site if they’re browsing from mobile?

To detect mobile devices and serve a mobile-optimized version of the website, you can use the navigator.userAgent property to check for common mobile user agents. For example:

}

How to use navigator.userAgent to detect browser type and display content based on the specific browser?

Alright, so, there might be a unique use case where you want to detect a specific browser, such as Chrome and Firefox (or in this case, Android and iPhone), and then use that data to display specific content. This approach is often used to provide/change download links for specific browsers.

In such a case, you can use the following function.

TouchEvent

One method to detect mobile users is to check if the device has a touch screen.

Using the GlobalEventHandlers.ontouchstart property you can make a simple check to see how the user interacted with your app. If the interaction came from a touch screen, you can then return a mobile version of the app or page.

if ("ontouchstart" in document.documentElement) { } else { }

Touch-screen devices like Surface do not have this property. So, users coming from desktop-based touch devices will still see the desktop version of your pages.

Window.matchMedia()

The Window.matchMedia() is one of the best properties for detecting mobile users with JavaScript. And it is so because it lets you interact with CSS directly.

In a lot of cases, media queries are superior because they have built-in mobile detection tools. For example, you can make a call to check if “pointer:coarse” is true.

This specific statement validates whether the device’s pointer is fine or coarse.

let isMobile = window.matchMedia("(pointer:coarse)").matches;

Alternatively, the device might have both a fine and coarse pointer. For this use case, we can check if any pointers are coarse.

let isMobile = window.matchMedia("(any-pointer:coarse)").matches;

Keep in mind that this only validates the query as true or false. A more refined way to check for mobile devices is to use media queries directly.

let isMobile = window.matchMedia("only screen and (max-width: 480px)").matches;

This query will directly check the max-width of the device and assert whether it matches the criteria. Again, this is quite a lot of work for getting all devices correctly. As such, it’s easier to use a pre-built library with all the device types already defined.

Useful in certain contexts

Over the years, there have been many JavaScript properties for detecting device types. Many of them got deprecated, but most others got integrated into libraries. Which also happens to be the best way to do proper mobile detection.

Last but not least, most modern frameworks already include mobile detection as part of the framework itself. It’s worth looking into if you don’t want to do all the legwork.

Libraries for Detecting Mobile Devices

This section will list the most popular JavaScript libraries for detecting mobile devices. Again, I emphasize that these are specific to JavaScript. Refer to the docs for proper implementation in your app.

UAParser.js

However, what makes it so popular is the fact that you can parse hundreds of device variations. And, all of it is very well documented. You can go from practical device vendors to more intricate detection patterns like CPU architecture.

mobile-detect.js

This is a fairly straightforward port of the Mobile Detect library for PHP, provided to the community by Heinrich Goebl. The library itself uses User-Agent for detection, so as we discussed earlier – not the best option.

Still, it should do the job when it comes to practical HTML templates or portfolio projects.

isMobile

Here we have another take on the User-Agent Navigator property from Kai Mallea. While still a simplistic solution, I like that isMobile provides a variety of specifications. For example, you can test for any mobile devices or specific ones like phone or tablet.

react-device-detect

Are you a chúng tôi developer?

Then this library from Michael Laktionov is for you. It works as you would expect – first the library detects device type, then renders the view based on that type. Works flawlessly with component integration, and can be further customized through API calls.

One interesting fact is the number of selectors this library includes. It covers devices like smart TVs, wearables, a variety of iPhone devices, and much more. This gives you a broad selection of design choices when building an app for a specific device.

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