(N ^= 1)

I was a bit stumped by this, I have not seen this before in JavaScript. Chances are you may not have seen it before either.

I wrote a quick little JSFiddle to try and see what it does. But before I get into that I thought I should get into where I found it.

I wanted to find a way to validate a credit card. To know roughly if it is valid before leaving a form. I stumbled across something called, “The Luhn Formula.”

This Luhn formula sparked my interest so I started reading about it, here, and found it interesting. I was looking at some solutions that others have come up with and found an interesting one, here. 

On line 16, I found: (bit ^= 1)and instantly started searching to figure out what it is. I couldn’t find an answer though so I wrote a fiddle that can be found at https://jsfiddle.net/Antmanx2/cfn3zhsm/.

I got the following results:

• A= 0 Value= 1
• A= 1 Value= 0
• A= 2 Value= 3
• A= 3 Value= 2
• A= 4 Value= 5
• A= 5 Value= 4
• A= 6 Value= 7
• A= 7 Value= 6
• A= 8 Value= 9
• A= 9 Value= 8
• A= 10 Value= 11

After looking at the results I found the pattern, when Even it adds one to N and when odd it subtracts one from N. 

Not something I have used and have never seen it in JavaScript so I thought I would share. Hope you find this helpful!

The post Have you seen this? appeared first on Computer Passion.

When you need to write logic for each specific date in a date range. One way to iterate through the days is using something like this method.

private IEnumerable<DateTime> EachDay(DateTime from, DateTime thru)
{
     for (var day = from.Date; day.Date <= thru.Date; day = day.AddDays(1))
     {
          yield return day;
     }
}

This method could then be called like:

foreach (DateTime day in EachDay(StartDate, EndDate))

If  you have not used yield before there are many great articles out there already that can explain in more detail, however it basically is returning each value per cycle before going back to the loop. So this would talk to this method, return a single day before returning to the next day.

Source

The post Iterate Through a Date Range. appeared first on Computer Passion.

Handy little snippet of code for checking for null before calling ToString().

I found this little bit of code pretty clever and handy.

Let us avoid those errors:

private static string ToSafeString(object obj)
{
   return (obj ?? string.Empty).ToString();
}

Source

The post Check for null before calling ToString() appeared first on Computer Passion.

Resharper is a must have tool for any .net developer.

Resharper helps by speeding up development time, helps keep naming conventions the same (amongst many other benefits), provides useful insights while coding, and so much more. I honestly would hate to code without Resharper, if you have never tried it give it a swirl (free for 30 days).

You can find it from the Jet Brains website.

The post Resharper for Visual Studio appeared first on Computer Passion.

Is my web technology compatible?

Ever need to know quickly and easily if a web technology is compatible with the browser users of your website are using?

This handy website will cover most web technologies and presents it in an easy to read and understand format.

You can check out this online tool at caniuse.com

The post Great tool for checking Browser Capabilities appeared first on Computer Passion.

I came across the site Flexbox Froggy while speaking with coworkers. Flexbox Froggy is a very helpful site in learning what flexbox is all about. If you have never used Flexbox before I strongly recommend checking it out. If you are curious about flexbox or just getting started with it check it out here: Flexbox Froggy.

A more detailed tutorial can be found here.

What do you know?

Do you know of other great tutorials or have suggestions let us know in the comments section, only requires you sign up for a free account.

The post Flexbox Froggy – Learn Flexbox basics quickly and easily. appeared first on Computer Passion.

Yamm Bootstrap Library Delivers the Megamenu

I came across this Bootstrap Library, Yamm, that I think could be very useful and time saving. Personally I have not used it so let me know what you think about it. The sites I have seen utilize the menu seems smooth and looks great. For people like me that are more functionality focused this could be a huge time saver.

I am a fan of the whole megamenu with content, images, and groupings. It seems to put things in an organized manor that is just more eye catching than old dropdown menu items.

Check out Yamm

The post Megamenu Library for Bootstrap appeared first on Computer Passion.

Ever have a situation where you have to push a new JavaScript file but know you have users that might have it cached, or tired of having to refresh the page to get the latest JavaScript file?

I ran across this issue today and found a nice solution that worked as I needed it to.

As part of the src line in your call to the JavaScript file add a version to the end of it using ?VersionNumber as shown below:


<script type="text/javascript" src="filename.js?0001"></script>

Each time a change is made simply change the version number and no more having to fight JavaScript file caching.

Hope you find this helpful, I know I did. Have a better solution? I would love to hear about it, please leave a comment.

The post Browser Caching JavaScript Files – Lets force it to update! appeared first on Computer Passion.

As I continue to improve my website and find better ways, things may change up a bit. I have changed the navigation a bit and soon will be changing how my categories are organized. Please bare with me as I try to get this all sorted out, I want to do it the correct way now so that in the future I do not have a huge undertaking to fix everything.

If you have any issues or suggestions please feel free to leave comment or post on the forums (also a work in progress.)

The post Where did it go? appeared first on Computer Passion.

BlackWasp is a great site that has tutorials and definitions. It is really good at explaining difficult concepts in an easy to understand way and covers a wide range of topics. I recommend this site for all levels of programmers and especially anyone that is new.

They have topics from C# fundamentals, unit testing, and many more.

Check out BlackWasp

The post Learning to code or need a Refresher, BlackWasp can help! appeared first on Computer Passion.