Visitor Design Pattern

Superb awesome explanation You really helped me a lot
Thanks feels very tiny word for your work

This was super helpful!

10yr old video and helped me a lot Derek. Glad that I was already a sub and found this video from you, you always have the best examples!

Hey, I just wanted to let you know that these tutorials were amazing and made it very easy to understand these design patterns. Thank you!

the legend

Why not simply define a function calculateTax() that is implemented for each one of the classes Liquor, Tobacco and Necessity? The the code would be simpler: don't need a TaxVisitor, simply create milk and then milk->calculateTax(). As milk is a Necessity, it would call the correct calculateTax() function, wouldn't it?

Brilliant!

Hey Derek. I've just finished your entire design patterns series. Thank you for this. They covered this stuff in university but I finally feel like I get it now.

Digged my way through the whole series. Several saturdays well spend!
Amazing how I only discovered this channel 10 years after this groundbreaking series was first publisched. I remember from those days good tutorials were scarce and weren't always very easy on the ear (not you, Kahn Academy). With the poll at the end it struck me how much of it you did right, despite probably having very little to go on, and figuring things out as you went along.

Hi, just found out these videos 10 years after. They are the best explanation I've seen for GOF design patterns! Thank you for making this.

Your voice is excellent! Like a British Broadcaster named Jerimy Clarkson.

its 2022 and still your videos are the best 🙂

best to the topic I have ever seen / thank you

Thanks for the video! It explained the concept very simply and clearly.

I know this was from forever ago, but I just want to say your style of videos is extremely informing and easy to follow. Well done!

Your videos on design patterns are simply the best!!!!

Godsend video for sure, where did you learn how to do all this? are you just good at reading technical textbooks? or did you have a really good teacher? or how did this happen?, I'm always curious like how things came to be

Your video's are a godsend

very well made video. thank you

Awesome video, super helpful and concise. Ur a G Derek Bannanas .

2 words "thank you"

The thing I don't like about this pattern is that it needs an a really good explanation in order to understand it.

Milk was 3.47 in 2012 ? Still costs the same after 9 years.

this is amazing and such a concise explanation! <3

This video was the first time I was taught Visitor pattern, and I feel like I really learned it well. Nicely done! Your Factory Pattern really helped me out for a game project I'm doing in school. I learn better from your videos than from my class!

I like the order in which you listed the items - liquor, tobacco and then food :) Helpful video by the way!

Why it is important to have a accept method within each of item? For example: Can't we directly call taxCalc.visit(milk) instead of milk.accept(taxCalc)? In that way, we absolutely have to make no change in the item object.

I vote for android development!

This is probably the easiest design pattern

Must have a donate button !!!!

Hi.
After some times of thinking about it.

What the difference between Visitor and Strategy ?

I Think maybe visitor helps to make a global report about what your class have inside her, but you want to use this global report for many very different things (it's scray how it can be different uses) when Strategy is one family of algorithms so it's restricted, visitor is not.

Am I true or not ?
Thanks.

greeeeeeeeeeeeeeeat

Doesn't visitor pattern violate SRP or LSP? Maybe i want to add method only for type X but not Y

thank you!

Hi Sir, I just went through your video. It is very simple and straight forward.
I have a question on this content.
In client.cs Instead of calling milk.accept(taxCalc); Why cant we write TaxCalc.Visit(milk);
I don't understand why we need an IVisitable interface and the accept method at all.

The voice 🔥🔥🔥🔥

I'm watching a 7 year old video because design patterns never gets old or get updated.

To be honest you explain codes and DP in the best way! thanks a lot.

This does not do a good job of explaining the need for the visitor pattern. Based on your example in main, what is stopping you from just calling taxCalc.visit(milk); instead of using accept? It makes it seem like the accept functionality just adds extra baggage in this scenario.

Excellent, thank you very much

the easiest implementation of this pattern is when your language supports extensions methods, e.g. c#, swift, kotlin (assuming your visitor does not need manage state)

I LOVE YOU

Good presentation. Am I the only one who thinks that this pattern violates Open-Closed?

func simplewaytotaxwithoutbeinganidiot(x float) float {
return x*0.15
}


beerprice := 4.00;


newPrice = simplewaytotaxwithoutbeinganidiot(beerprice);

YOU ARE A G O D

GREAT VIDEO! Help! i need urgent explanation on how to draw a polyline using the visitor design pattern...Can if you can please send me your email so i can contact you directly that will be appreciated

Such a nice video series!! Plus you have such a cute voice :)

I tried at least 5 other sources to understand this design pattern but I failed. Finally, I got it by watching only half of your video while I never did java. Really good job.

I LOVE YOU DEREK