C# 10.0 All-in-One for Dummies – Page 2 – John's Random Thoughts and Discussions

Checking for Mobile Friendliness

This is an update of a post that originally appeared on January 6, 2016.

Is your application mobile friendly? It seems simple enough, but the answer can be very tough to come by. This whole concept of mobile device friendliness sometimes seem like an enigma wrapped in a Zen riddle. There is actually a difference between sites that are mobile friendly and those that are mobile responsive, in that a mobile responsive design does a lot more for the mobile users (and is always mobile friendly by default).

Most development tools today make a strong attempt at helping you create mobile friendly applications. In addition, new technologies and tools are helping developers create useful applications. Fortunately, vendors such as Google are now making it possible for you to verify that your site is mobile friendly with an easy to use check. All you need to do is point your browser to https://www.google.com/webmasters/tools/mobile-friendly/, enter an URL, and click Analyze. You get a quick answer to your question as shown here within a few seconds.

Verify that your site will support mobile users by performing a mobile friendly check. — Output from a Successful Mobile Friendly Check

The page contains more than just a validation of the mobile friendliness of your site. When you scroll down, you see a simulated output of your site when viewed on a smartphone. The view is important because it helps you understand how a mobile user will see your site, versus the view that you provide to desktop and tablet users. It’s important not to assume that mobile users have the same functionality as other users do. Here’s the simulated view for my site.

Mobile users may see something different than you expect, even when your site is mobile friendly. — Verify the Smartphone View of Your Site

As more and more people rely on mobile devices to access the Internet, you need to become more aware of what they’re seeing and whether they can use your site at all. According to most authorities, more users access the Internet using mobile devices today, than other devices, such as laptops, desktops, or tables. If you don’t support mobile devices correctly, you lose out on the potential audience for your site. By making the switch to mobile devices and apps, in particular, you have the ability to not only widen your audience, but you also have a better chance of being able to increase your revenue too. Most successful businesses have made the transition to mobile as they don’t want to lose any customers (but the quality of presentation varies greatly and is sometimes useless), as it may mean that they make less money than they could otherwise could from sales and that the influence of their site is far less. Let me know your thoughts about mobile device access at [email protected].

Considering the Authentication of Credit Cards in Web Settings

This is an update of a post that originally appeared on November 27, 2015.

I often write a blog post with the hope that things will change for the better at some point because there are often strategies for making things better if someone will simply implement them. I don’t know about you, but I’m buying more and more items online, which means using my credit card more often than before. That’s why articles like, How Serious a Crime Is Credit Card Theft and Fraud?, attract my attention.

One of the biggest problems is the use of static technology. For example, the Credit Verification Value (CVV), a three or four digit addition to a credit card number, is supposed to help safeguard the credit card. It doesn’t appear as part of the card data accessible through the magnetic strip or the chip. The CVV is actually printed on the card as a separate verification for venues such as web applications. The only problem is that this number is static-it remains the same for however long you own the card. Therefore, once a hacker discovers the CVV, it no longer provides any sort of security to the card owner. Interestingly enough, some sites online will sell you both credit card numbers and their associated CVV. The hackers win again.

A solution to this problem is to change the CVV periodically. Unfortunately, trying to change a printed CVV is impossible without replacing the card. One possible way to overcome this problem involves the addition of an e-paper space on the back of the card that would allow the credit card companies to change the CVV, yet keep it out of the magnetic stripe or chip. A lot of devices currently use e-paper, such as Amazon’s Kindle. The technology provides a matte paper-like appearance that reflects light similar to the way in which paper reflects it, rather than emitting light like an LED does. The difference is that e-paper is often easier to read. There is at least one company offering such a solution today as described at Gemalto Dynamic Code Card – for a more serene online shopping experience.

Oberthur (now Idemia), the inventor of the Motion Code technology used to create the updated CVV, isn’t saying too much about how the technology works. There must be an active connection between the card and a server somewhere in order to update the CVV once an hour as specified in the various articles on the topic. The only problem is in understanding how the update takes place. If the technology relies on something like a Wi-Fi or cell connection, it won’t work in rural areas where these connections aren’t available. Even so, the technology does promise to reduce the amount of fraud that currently occurs-at least, until hackers find a way to thwart it.

What is your feeling about credit card data protection? Are you a business entrusted with protecting your customers’ information? If so, maybe you should find out more here about the consulting available in this particular field of business management to ensure that you’re following the law to the letter. Does Motion Code technology actually provide a promising solution or is it another dead end? How do you deal with potential fraud when creating your applications? Send your ideas to me at [email protected].

Considering Perception in User Interface Design

This is an update of a post that originally appeared on January 24, 2014.

The original version of this article had humans seeing images in as little as 13 ms. Nothing much has really changed since then. I read a few articles recently that reminded me of a user interface design discussion I once had with a friend of mine. First, let’s discuss the articles:

The first, Everything we see is a mash-up of the brain’s last 15 seconds of visual information, says that humans can actually see something in as little as 15 ms. That short time frame provides the information the brain needs to target a point of visual focus.
The older second article, ‘Sixth Sense’ Can Be Explained by Science, explains how the sixth sense that many people relate as being supernatural in origin is actually explainable through scientific means. The brain detects a change-probably as a result of that 15 ms view-and informs the rest of the mind about it. However, the change hasn’t been targeted for closer inspection, so the viewer can’t articulate the change.
The third article, The silent “sixth” sense, is a more scientific and slightly modernized view of the second article. In short, you know the change is there, but you can’t say what has actually changed.

So, you might wonder what this has to do with website design. It turns out that you can use these facts to help focus user attention on specific locations on your site. Now, I’m not talking here about the use of subliminal perception, which is clearly illegal in many locations. Rather, it’s possible to do as a friend suggested in designing a site and change a small, but noticeable, element each time a page is reloaded. Of course, you need not reload the entire page. Technologies such as Asynchronous JavaScript And XML (AJAX) make it possible to reload just a single element as needed. (Of course, changing a single element in a desktop application is incredibly easy because nothing special is needed to do it.) The point of making this change is to cause the viewer to look harder at the element you most want them to focus on. It’s just another method for ensuring that the right area of a page or other user interface element gets viewed.

However, the articles also make for interesting thoughts about the whole issue of user interface design. Presentation is an important part of design. Your application must use good design principles to attract attention. However, these articles also present the idea of time as a factor in designing the user interface. For example, the order in which application elements load is important because the brain can perceive the difference. You might not consciously register that element A loaded some number of milliseconds sooner than element B, but subconsciously, element A attracts more attention because it registered first and your brain targeted it first. This essentially explains the difference between UX and UI, since the two are eternally intermingled in the world of development.

As science continues to probe the depths of perception, it helps developers come up with more effective ways in which to present information in a way that enhances the user experience and the benefit of any given application to the user. However, in order to make any user interface change effective, you must apply it consistently across the entire application and ensure that the technique isn’t used to an extreme. Choosing just one element per display (whether a page, window, or dialog box) to change is important. Otherwise, the effectiveness of the technique is diluted and the user might not notice it at all.

What is your take on the use of perception as a means of controlling the user interface? Do you feel that subtle techniques like the ones described in this post are helpful? Let me know your thoughts at [email protected].

Web Page Units of Measure

This is an update of a post that originally appeared on October 23, 2013.

There are ways today of avoiding any thought of what units of measure the Web page you’re working on uses. For example, I use products like WordPress all the time now to make the task of creating content quickly a lot easier. I don’t ever think about the units of measure I’m using when working with these products. However, when designing an interface for an Android or C# application (as examples), I sometimes do need to think about units of measure because I’m more intimately involved in the user interface design process. Today, applications need to work everywhere on a large number of devices, all of which have different characteristics, so units of measure can become an issue. So, it’s entirely possible that you could create a nearly unlimited amount of content for a website without ever worrying about units of measure, but this blog post is for those times when it does matter.

Some units of measure work better than others do in obtaining a specific result. For example, when you specify placement in pixels (px), you tell the browser to define element placement with regard to the physical units of a display. This is the most precise, yet least flexible, method of defining units of measure. In addition, it can create issues with mobile devices because these devices typically don’t offer that many pixels of display area and may not allow scrolling of information that doesn’t appear in a single screen (the part that appears to the right and toward the bottom of the page).

More flexible units of device-specific measure include the inch (in), centimeter (cm), and millimeter (mm). In this case, the browser converts the measurement to pixels using the device’s conversion metric. For example, a typical PC display uses 96 pixels-per-inch. However, the user can change the metric so that an inch could consume 120 pixels instead (making the elements larger than normal). Whether this flexibility solves the problem of working with mobile devices depends on the mobile device and the metric it uses to convert physical units to pixels.

Besides device and physical measures, you can also use printer’s measures that include the point (pt) and pica (pc). These units of measure theoretically work the same as physical measures because a point is 1/72^nd inch and a pica is 12 points (or 1/6^th inch). In reality, it’s possible that a browser will convert the units of measure based on the size of the fonts that the device uses. However, you can’t count on this flexibility and must assume that these printer’s measures are simply a different kind of physical measure.

Fortunately there are two units of measure that are guaranteed to reflect the size of a font on the display. The em is a measure of the actual font size. One device may use a 12 point font while another device uses a 10 point font. An em will equal 12 points on the first device and 10 points on the second device without any modification of the code on your part. This feature makes the page quite flexible and usable with any device. The other unit of measure is the ex, which is the measure of the x-height of a font (the median of all of the characters in a particular letter set). As with the em, the ex automatically scales to consider the point size of characters used by a particular device.

All of the units of measure so far are absolute. You place elements on a screen in a precise position. Modern Web design dictates that pages employ Responsive Web Design (RWD) to ensure that the page will work on any device. A part of RWD is to use relative placement wherever possible so that the page and its elements automatically resize to meet the needs of a device. You use the percentage (%) unit of measure in this case, where an element uses a percentage of the available space, whatever that space might be. Of course, this approach means that all devices see the entire page. However, a disadvantage of this approach is that the elements might be so small on some devices as to make them unusable.

The article, CSS values and units, provides you with more information about units of measure as they apply to Cascading Style Sheets (CSS). These guidelines generally apply to other working environments as well. What are your thoughts about units of measure? Which do you use most often? Let me know at [email protected].

In Praise of Dual Monitors

This is an update of a post that originally appeared on February 5, 2014.

In reading many of my old blog posts, I’m finding that many of the things I said way back when apply equally well today. I’ve received email from budding developers who use their smartphone to code. Just how they perform this trick is beyond me because I squint at the screen performing the simplest of tasks and often find that my fingers are two sizes too big. I have tried coding on a tablet, a laptop, and (oddly enough) my television. While they do work, they’re not particularly efficient, so I’ll stick with my dual-monitor desktop system for coding.

Yes, I know that some developers use more than just two monitors, but I find that two monitors work just fine. The first monitor is my work monitor—the monitor I use for actually typing code. The second monitor is my view monitor. When I run the application, the output appears on the second monitor so that I can see the result of changes I’ve made. Using two monitors lets me easily correlate the change in code to the changes in application design. Otherwise, I’d be wasting time switching between the application output and my IDE.

I also use two monitors when writing my books. The work monitor contains my word processor, while my view monitor contains the application I’m writing about. This is possibly one time when a third monitor could be helpful—one to hold the word processor, one to hold the IDE, and one to view the application output. However, in this case, a third monitor could actually slow things down because the time spent viewing the output of an example is small when compared to creating a production application.

The concept of separating work from the source of information used to perform the work isn’t new. People have used the idea for thousands of years, in fact. For example, when people employed typewriters to output printed text, the typist employed a special stand to hold the manuscript being typed. The idea of having a view of your work and then another surface to actually work on is used quite often throughout history because it’s a convenient way to perform tasks quickly. By employing dual monitors, I commonly get between a 15 percent to 33 percent increase in output, simply because I can see my work and its associated view at the same time.

Working with dual monitors not only saves time, but can also reduce errors. By typing as I view the output of applications, I can more reliably relate the text of labels and other information the application provides. The same holds true when viewing information sources found in other locations. Seeing the information as I type it is always less likely to produce errors.

Don’t get the idea that I support using dual monitors in every situation. Many consumer-oriented computer uses are served just fine with a single monitor. For example, there isn’t a good reason to use two monitors when viewing e-mail in many cases—at least, not at the consumer level (you could make a case for using dual monitors when working with e-mails and a calendar to manage tasks, for example). Dual monitors commonly see use in the business environment because people aren’t necessarily creating their own information source—the information comes from a variety of sources that the user must view in order to use reliably.

Do you see yourself using dual monitors? If you use such a setup now, how do you employ it? Let me know at [email protected].

Choosing Variable Names

This is an update of a post that originally appeared on January 17, 2014.

It often surprises me that developers seem to choose completely useless variable names like MyVariable when creating an application. Although MyVariable could be an interesting variable name for an example in a book, it never has a place in any sort of production code. Even then, I try to create book examples with meaningful variable names, especially when getting past the initial “Hello World” example. Variable names are important because they tell others:

What sort of information the variable stores
When the variable is commonly used
Where the variable is used
How to use the variable correctly
Why the variable is important

In some cases, the variable name could even indicate who created the variable; although, this sort of information is extremely rare. If you never thought a variable name should contain all that information, then perhaps you haven’t been choosing the best variable names for your application.

Even with these restrictions in place, choosing a variable name can be uncommonly hard if you want to maximize the name’s value to both yourself and other developers. Some organizations make the selection process easier by following certain conventions. If you don’t have an organizational style guide for variable naming, modern programming languages like Python commonly provide a style guide for you to use. These style guides often consider a great deal more than simply variable naming and include issues like the amount of indentation to use. In some respects, they become quite draconian in their approach. Other style guides, like the one for C#, are less time consuming to learn, which is a good thing because most developers have better things to do with their time than to learn some of these nitpicky details. A few languages suffer from an abundance of style guides, like C++. It’s best to choose one of them, such as the Google C++ Style Guide, and stick with it.

However, let’s say that you want to create your own style guide for your organization to use because you use multiple languages and having a different style guide for each language seems just a bit absurd, not to mention adding needless complexity. In this case, you need to ask yourself a series of questions to determine how you want the style guide to work, such as these:

What sort of casing do you want to use for what types of variables?
What information does the variable contain (such as a list of names)?
How is the variable used (such as locally or globally, or to contain coordinates, or a special kind of object)?
When appropriate, what kind of information does the variable contain (such as a string or the coordinate of a pixel on screen)?
Is the variable used for a special task (such as data conversion)?
What case should prefixes, suffixes, and other naming elements appear in when a language is case sensitive?

The point is that you need to choose variable names with care so that you know what they mean later. Carefully chosen variable names make it possible for you to read your code with greater ease and locate bugs a lot faster. They also make it easier for others to understand your code and for you to remember what the code does months after you’ve written it. However, most important of all, useful variable names help you see immediately that a variable is being using the wrong way, such as assigning the length of a name string to a coordinate position on screen (even though both variables are integer values). Let me know your thoughts about variable naming at [email protected].

Sending Comments on My Books

This is an update of a post that originally appeared on February 23, 2012.

I regularly receive a stack of e-mail about my books. Readers question everything and it makes me happy to see that they’re reviewing my books so closely. It means that I’m accomplishing my principle goal, helping you understand computers in every possible way so that you can be more productive and accomplish tasks with less effort. When I make something easier for someone and they tell me about it, the grin extends from one side of my face to another. It really makes my day.

Some readers are still asking me if it’s OK to send me comments. I definitely want to see any constructive comment that you have. Anything that helps me understand your needs better makes it possible for me to write better books. I really do want to hear from you. The main element that I need to obtain a usable comment is that it’s constructive. A comment that lacks details isn’t helpful because I’ve written so many books. Emotional comments without any substance are especially hard to deal with because they leave me wondering what you need from me. Here are some of the things you can do to create a constructive comment:

What is the title of the book you’re reading (be sure to include the edition number, which is usually right on the cover unless it’s a first edition)?
Are you using the downloadable source code if this is a programming book?
Did you install the recommended version of any required software using the instructions found in the book?
Which page contains the error (if you’re using Kindle or other electronic media, please provide a chapter number and section title as a minimum)?
What do you view as an error on that page?
How would you fix the error?
What sort of system are you running?
When did you encounter the problem?

The more information you provide, the easier it is for me to understand the issue and provide you with feedback. In many cases, I’ll upload the fix to my blog so that everyone can benefit from the response (so be sure you keep an eye on my blog for new entries). I work hard to ensure that my books are as error free as possible, but everyone makes mistakes. Also remember that sometimes mitigating factors, such as differences in software versions or anticipated hardware, make it appear that there is an error in the book when you’re really looking at a different in environment. Help me provide you with better books—send me comments!

There are a few things that I won’t do for you. I won’t help you pass an exam at school. Your learning experience is important to me, which means that I want you to continue your education by working through the instruction on your own. I also don’t provide free consulting. This means I won’t check the code that you created on your own for errors. In addition, if you don’t use the downloadable source, be sure to read Verifying Your Hand Typed Code for restrictions on the level of support that I provide. I’ll help you with any book-specific question, but I draw the line at that point. Let me know if you have any input or insights on my books at [email protected].

Book Reviews – Doing Your Part

This is an update of a post that originally appeared on October 4, 2013.

Readers contact me quite a lot about my books. On an average day, I receive around 65 reader e-mails about a wide range of book-related topics. Many of them are complimentary about my books and it’s hard to put down in words just how much I appreciate the positive feedback. Often, I’m humbled to think that people would take time to write.

There is another part to reader participation in books, however, and it doesn’t have anything to do with me—it has to do with other readers. When you read one of my books and find the information useful, it’s helpful to write a review about it so that others can know what to expect. I want to be sure that every reader who purchases one of my books is happy with that purchase and gets the most possible out of the book. The wording that the publisher’s marketing staff and I use to describe a book represents our viewpoint of that book and not necessarily the viewpoint of the reader. The only way that other readers will know how a book presents information from the reader perspective is for other readers to write reviews. A good review will tell:

What you liked about the book
How it met your needs
What it provides in the way of usable content
Whether you liked any intangibles, such as the author’s writing style
When you used the content to obtain a new job or learn a new skill
Who recommended the book to you

The review should also present any negatives (obviously, I want to know about the flaws, too, so that I can correct them in the next edition of the book and also discuss them on my blog):

Did the book provide enough detailed procedures needed to accomplish a task?
Are significant technical flaws and why do you feel they’re an issue?
Are there enough graphics to augment the text and make it clearer?
Is the source code useful?

Many reviewing venues, such as the one found on Amazon, also ask you to provide a rating for the book. You should rate the book based on your experience with other books and on how this particular book met your needs in learning a new topic. The kind of review to avoid writing is a rant or one that isn’t actually based on reading the whole book. As always, I’m here (at [email protected]) to answer any questions you have and many of your questions have appeared as blog posts when the situation warrants.

So, just where do you make these reviews? The publishers sometimes provide a venue for expressing your opinion and you can certainly go to the publisher site to create such a review. I personally prefer to upload my reviews to Amazon because it’s a location that many people frequent to find out more about books. You can go to the site, click Write a Customer Review (near the bottom of the page), and then provide your viewpoint about the book.

Thank you in advance for taking the time and effort required to write a review. I know it’s time consuming, but it’s an important task that only you can perform.

Using the Set Command to Your Advantage

This is an update of a post that originally appeared on February 24, 2014.

A short while ago, I created a post about the Windows path. A number of people wrote me about that post with questions. Yes, you can use the technique for setting the Path environment variable to set any other environment variable. The Windows Environment Variables dialog box works for any environment variable—including those used by language environments such as Java, JavaScript, and Python. Windows doesn’t actually care what sort of environment variable you create using the method that I discuss in that post. The environment variable will appear in every new command prompt window you create for either a single user or all users of a particular system, depending on how you create the environment variable.

A few of you took me to task for not mentioning the Set command. This particular command appears in Microsoft Windows Command Line Administration Instant Reference. It’s a useful command because you can temporarily configure a command prompt session to support a new set of settings. When the session is ended, the settings are gone. Only those settings you create as part of Environment Variables window have any permanence. There are other tricks you can use, but using Set for temporary environment variables and the Environment Variables window for permanent environment variables are the two most common approaches.

In order to see the current environment variables you simply type Set and press Enter at the command line. If you add a space and one or more letters, you see just the matching environment variables. For example, type Set U and press Enter to see all of the environment variables that begin with the letter U.

To set an environment variable, you add the name of the variable, an equals sign (=), and the variable value. For example, to set the value of MyVariable to Hello, you type Set MyVariable=Hello and press Enter. To verify that MyVariable does indeed equal Hello, you type Set MyVariable and press Enter. The command prompt will display the value of MyVariable. When you’re done using MyVariable, you can type Set MyVariable= and press Enter. Notice the addition of the equals sign. If you ask for the value of MyVariable again, the command prompt will tell you it doesn’t exist.

Newer versions of the command prompt provide some additional functionality. For example, you might set MyVariable within a batch file and not know what value it should contain when you create the batch file. In this case, you can prompt the user to provide a value using the /P command line switch. For example, if you type Set /P MyVariable=Type a value for my variable: and press Enter, you’ll see a prompt to enter the variable value.

It’s also possible to perform math with Set using the /A command line switch. There is a whole list of standard math notations you can use. Type Set /? and press Enter to see them all. If you write application code at all, you’ll recognize the standard symbols. For example, if you want to increment the value of a variable each time something happens, you can use the += operator. Type Set /A MyVariable+=1 and press Enter to see how this works. The first time you make the call, MyVariable will equal 1. However, on each succeeding call, the value will increment by 1 (for values of 2, 3, and so on).

Environment variables support expansion and you can see this work using the Echo command. For example, if you type Echo %MyVariable%, you see the value of MyVariable.

However, you might not want the entire value of MyVariable. Newer versions of the command prompt support substrings. The variable name is followed by a :~, the beginning position, a comma, and the ending position. For example, if you place Hello World in MyVariable, and then type Echo %MyVariable:~0,5% and press Enter, you see Hello as the output, not Hello World. Adding a negative sign causes the expansion to occur from the end of the string. For example, if you type Echo %MyVariable:~-5% and press Enter, you see World as the output.

The Set command is a valuable addition to both the administrator’s and programmer’s toolkit because it lets you set environment variables temporarily. The Set command figures prominently in batch file processing and also provides configuration options for specific needs. Let me know about your environment variable questions as they pertain to my books at [email protected].

Adding a Location to the Windows Path

This is an update of a post that originally appeared on February 17, 2014.

A number of my books tell the reader to perform tasks at the command line. What this means is that the reader must have access to applications stored on the hard drive. Windows doesn’t track the location of every application. Instead, it relies on the Path environment variable to provide the potential locations of applications. If the application the reader needs doesn’t appear on the path, Windows won’t be able to find it. Windows will simply display an error message. So, it’s important that any applications you need to access for my books appear on the path if you need to access them from the command line.

You can always see the current path by typing Path at the command line and pressing Enter. What you’ll see is a listing of locations, each of which is separated by a semicolon as shown here (your path will differ from mine).

Using the Path command displays the current path.

In this case, Windows will begin looking for an application in the current folder. If it doesn’t find the application there, then it will look in C:\Python33\, then in C:\Program Files (x86)\NVIDIA Corporation\PhysX\Common, and so on down the list. Each potential location is separated from other locations using a semicolon as shown in the figure.

There are a number of ways to add a location to the Windows path. If you only need to add a path temporarily, you can simply extend the path by setting it to the new value, plus the old value. For example, if you want to add C:\MyApp to the path, you’d type Path=C:\MyApp;%Path% and press Enter. Notice that you must add a semicolon after C:\MyApp. Using %Path% appends the existing path after C:\MyApp. Here is how the result looks on screen.

Adding a path is a relatively simple process using the Path= command

Of course, there are times when you want to make the addition to the path permanent because you plan to access the associated application regularly. In this case, you must perform the task within Windows itself. The following steps tell you how.

1. Right click This Computer (or Computer) and choose Properties from the context menu or select Settings (or System in the Control Panel). You see the a Settings (System) window similar to the one shown here open (precisely what you see depends on which version of Windows you have, the figure shows Windows 10).

2. Click Advanced System Settings. You see the Advanced tab of the System Properties dialog box shown here.

The Advanced tab provides access to your permanent path in Windows.

3. Click Environment Variables. You see the Environment Variables dialog box shown here. Notice that there are actually two sets of variables. The top set affects only the current user. So, if you plan to use the application, but don’t plan for others to use it, you’d make the Path environment variable change in the top field. The bottom set affects everyone who uses the computer. This is where you’d change the path if you want everyone to be able to use the application.

There are paths that affect only the current user and those that affect the system as a whole.

4. Locate the existing Path environment variable in the list of variables for either the personal or system environment variables and click Edit. If there is no existing Path environment variable, click New instead. You see a dialog box similar to the one shown here when working with Windows 10 (other versions of Windows will show a different dialog box, but the purpose is the same, to edit the path).

Each path location appears on a separate line to make it easy to edit.

When you open a new command prompt, you’ll see the new path in play. Changing the environment variable won’t change the path for any existing command prompt windows. Having the right path available when you want to perform the exercises in my books is important. Let me know if you have any questions about them at [email protected].