Skip to main content

ECMAScript 5 Properties (Javascript)

I went to the Nottingham Geekup last night. The talk was by @firagabeatsrock. A good talk with some important points to watch out for about Javascript. 

I am blessed with being fairly au fait with Javascript so was familiar with the subject to a fairly in depth level. I made a couple of good notes however. One was to look at the Javascript performannce tool  http://jsperf.com/. As an uber geek I love performance tools. I like nothing more than obsessing over fiendery such as this. 

On the subject of performance, he pointed out that when using a for loop, don't refer directly to the length in the loop as javascript checks it every time. There is more to add to this story however. You can make life even worse by reffering to the length of a jquery collection in a for loop. I believe that is particularly slow and I now have the performance tool above to prove it :-)

The other thing I picked up on was a little reminder to look into the ECMAScript5 stuff. Now I have done a little example of the new properties and how they can have method bodies below...

https://gist.github.com/3623706

Ridiculous you say! That can already be achieved! Well, it can to a certain extend but you have very little control over people overriding your object and how you intended it to be used. I was going to go further into this subject but upon looking for supporting information, I found many people had already done a better job of explaining the matter. 

Take a peek at this blog and mind that you follow his update for even more interesting little tips....

http://ejohn.org/blog/ecmascript-5-objects-and-properties/

 

 

 

Comments

Popular posts from this blog

My home office upgrade wish list.

My home office is almost due an upgrade. I have been holding off until my youngest daughter is out of her cot as then we can finally dispatch the enormous monstrosity of a cot out from the kids bedroom and the drawers that are in my office can be banished giving me better access to my wonderful whiteboard. My other improvements will be purchasing a new, larger monitor. I currently work from a single 22ich Samsung which just doesn't cut it anymore, I did have two at some point but I can't recall what I did with it. I really enjoy using a touch screen so I think I will go for one of these 27inch Hannspree models that I have used before. I put a lot of hours in at home and whilst I have a reasonable chair I still tend to suffer with some back problems, so my next port of call will be to get a Varidesk for home. It works an absolute treat at work and just lets me switch stuff up when I feel like it. they take a reasonable amount of desk space up but I tend to leave my desk fairly

Arduino ethernet shield

My ethernet shield arrived this morning from Hong Kong. Looking forward to making a little Arduino based Web server! The price for the shield was only ?5 on ebay including delivery :-) super cheap considering how much they cost a couple of years ago.

Specflow

After listening to .Net Rocks with Scott Millett this week I felt a renewed enthusiasm for trying out some BDD. I downloaded Specflow and got straight on with the screen cast they have on their website. The video acts as a good introduction into how to get up and running in Specflow. Interestingly it also gave me a better insight into how bowling works. I have never really thought about it. I normally just wang the balls down the lane until the game is over! Specflow introduces the idea of writing the specification first. It uses a specific language called Gherkin which comes from Ruby land. You will need NUnit installed as well. An example of it is:  [edit: NUnit is what I have used up to now but Specflow is compatible with other testing frameworks aswell. See the comments section below.] Feature : Passwords In order to have a strong password As a new user or existing user changing my password I need to check if my password is alphanumeric and is greater than 6 characters Scenario