I always wondered why "is-a" and "has-a" relationship between objects is even worth mentioning, but now I know just how important they are. It's amazing how a small detail like this can completely change the way we approach programming.
I worked in both product and service industry of small, medium and large size company, i can see the clear understanding and explanation by the narrator on each of the topic and make an analogy to live code in my work. Very well explained in details, that too free of charge ,i recommend these videos to all the freshers or laterals who are working in java for upskilling.
Wish had explored your channel a bit earlier, awesome content on Low-level design(one-stop solution), Just feedback if you can arrange the videos of the playlist in what order to watch it will be really great for people.
Thank you Yash, not sure if youtube does not show playlist title and description, i have mentioned in both the place that Start from bottom and move Upward, let me check
public class PizzaShop { public static void main(String[] args) { BasePizza base = new VegDelight(); System.out.println(base.cost()); BasePizza customPizza = new ExtraCheese(new Mushroom(new Farmhouse())); System.out.println(customPizza.cost()); } }
Such awesome content, then its free. i cant explain how satisfied i am satisfied with your content. Thanks a lot bro. i have one request bro, whether you provide content free or paid, it does matter. just keep up. i have seen lots of videos and read books regarding design pattern. nobody explained like you. one thing makes your content unique, you deeply explain OOP concept behind design pattern.
Bhai ek number i never imagined that i can also understand LLD. Every said that LLD and HLD is hard but now i feel i can also learn these concepts. Thanks bro and can you suggest the book that help me to learn HLD and LLD. It will be very helpful.❤❤
this video is a GEM to the whole community, that too by a GEM..... hats off 2 u sir.. all this premium content for free , not possible on this whole planet itself,.... wish the java playlist would also become public / free someday , so that it can reach to every deserving candidate who cant afford the subscription at that point of time... s teachers like you are rare to find, your knowledge is uncomparable...
How do we handle the case where 2 features are not compatible with each other? For eg. Say in car configurator, user selected both chrome grill and black grill, one of them has to be removed. First the user selects chrome grill so price increases by 100, then user selects black grill so first we have to reduce price by 100 which is for chrome grill, then we add 80 for the black grill.
Super clear, I had a doubt: So according to this example "ExtraCheese" is a BasePizza due to indirect inheritance. So in Vehicle example, the decorator would extend the BaseVehicle. Power Steering would inherit from decorator and in-directly have a "is-a" relationship with BaseVehicle, right So in a way we are saying power-steering is a BaseVehicle so is it right? As power steering is not a Vehicle rather its a feature
really thank you sir for your huge efforts, but sir, if we keep a final ingredients price Map in Base Pizza itself, and keep Topping Map containing topping and its frequency, this can be solved much simply for calculating the price, but then again that solution is not scalable ig when toppings list and price need to be updated, thanks again.
Hi, Thanks for the great explanation. One small request could you please share the notes and the code that you are using for the explaination in each video. It would be beneficial.
//non decorator BasePizza p= new Margherita(); Topping t1= new ExtraCheese(); Topping t2 = new Veggies(); Topping t3= new Paneer(); Topping t4= new mushroom(); string tot = updateDesc(p.desc(), t1.desc()); tot = updateDesc(tot, t2.desc()); tot = updateDesc(tot, t3.desc()); tot = updateDesc(tot, t4.desc()); updateDesc(total,desc){ return total+ desc } //decorator BasePizza p= new Margherita(); p = new ExtraCheese(p) p = new Veggies(p) p = new Paneer(p) p = new mushroom(p) p.getdesc()
One very important question sir ji, when to interfere and when to use abstract can u make a detailed video in this, i think this will solve many questions of LLD in a thinking way
Yes, i know this, but while in interview when we say that i will create an abstract class or interface or concrete class they always ask why so? Why not interface inplace of abstract class, this is has been asked alot. So just a request when ever u make any any interface or abstract class please tell us the why interface or abstract please 🙏
I feel an improvment to this can be rather than creating concrete class for each topping create enum topping list class to dynamically update price for each topping
this code still maintains 'is-a' and 'has-a' relationship. So that is the requirement of decorator pattern . But here my concern with enum is not decorator pattern but with scalability and managebility lets say i want to add more methodd apart from Cost method like TotalCalories, totalProtein , totalCarbs etc. (lets say 10 -20 methods like this) how easy with enum to support this.
Thank you sir for this Amazing content. I have only one question that for every layer we have to create a new class so if our application will scale too much in that case we might have thousands of layers (Not specifically Pizza problem) so how can we solve that ?
Strategy Pattern & Decorator seems alike to me like IStrategy even BasePizza Can have only HAS-A relation with ToppingDecorator or list (to calculate cost for all types of toppings) right. Please help me to understand the difference , By the way thanks for the videos :) #Concept&&Coding
I think main task of Strategy Pattern is to remove redundant code where as Decorator Pattern is used to solve the problem of maintainability of our classes.
Thanks for the great content! Your videos are easy to understand. Can we please reorder the videos in the order, currently its in reverse order and we have to play videos manually each time.
Thanks for the explaination. Really loving LLD. Used interface instead of abstract class for BasePizza and Toppings. Do you think there will be an issue in this approach?
Wonderfully explained!! Its more like recurssion, so if imagine there are 100 of layes of decorator, then there might be overlapping subproblems. Can dp be used in that case?
Let's say we have created a pizza object with 3 toppings, how do we backtrack to know which toppings and which base pizza was selected while storing in the db ?
Hi, I understood this clearly, But I have a small doubt regarding Abstract class vs Interface. Can't we use Interface in BasePizza and ToppingDecorator, rather than using Abstract class? Other than this, I understood everything. Super explanation sir.
Firstly loving your videos! So thanks for that Q. Is this really good to do something like new ExtraCheeze( new ExtraPanner(new FarmHousePizza())))... B'coz not Basepizza object in ExtraCheese already contains a topping of ExtraPanner.... While if we were not to use Decorator design pattern... We would have had all the toppings on same level... (May be with a boolean flag) It might matter if we don't want cheese on top of panner but panner and cheese mixed very well... (Sty could not think of a better example)
Why are we using ToppingDecorator? If we are anyways inheriting Extracheese then can't we inherit it directly from BasePizza as we aren't doing anything in ToppingDecorator class?
I tried and understood and thought do I need abstract classes here cant I just use one Interface like BasePizza and implement it in my Base classes such as vegPizza and implement the same interface in topping classes but one chnage my topping class constructor should accept a BasePizza type Object; BasePizza pizza = new Extracheese(new Margherita());
In my approach, I used an interface for defining a behavior and then created multiple concrete classes implementing this interface, each representing a different behavior. This seems somewhat similar to the Decorator Pattern, where each decorator wraps an object and adds its behavior. However, I'm struggling to see a significant advantage of the Decorator Pattern over my approach in terms of scalability, flexibility, and maintainability, especially when considering the addition of new behaviors. In both cases, adding a new behavior seems to require just adding a new class without modifying existing ones. Could you help clarify the specific advantages of using the Decorator Pattern over this approach?
You have created A,B C different concrete classes. If you want to create new concrete classes with properties of lets say B , with decorator pattern you will have B1 , B2 etc. But without decorator pattern you might have to write more code to not only include the property of B but also its own new property. I hope this helps.
Hi, Suppose we have an abstract pizza class and an abstract toppings class which are inherited by concrete classes . Now, every pizza class has a list of toppings . So, when we calculate the cost, we just iterate over that list and compute the total cost. I have a big doubt that if only has-a relationship is solving this problem. Why do we need such a complex structure of has-a and is-a relationship existing at the same time and what extra advantage does decorator pattern bring into picture ?Looking forward to your reply to this question.
okay, could you please tell me, how you would solve the scenario where you have 1000s of combination like BasePizze, BasePizze + cheese , BasePizza + mushroom, Veggie + cheese and go on...... The biggest advantage decorator pattern adds up is control on number of classes if there are so so many combinations possible.
@@ConceptandCoding Thanks for your reply. Lets suppose Base pizza is extended by two Pizza class Veg and Non Veg Pizza. I have another ExtraAddOn class which is inherited by say cheese, mushroom, paneer and so on ... Now, I have a " vector extraList; " in Veg and Non Veg Pizza class. So, whatever combinations of ExtraAddOn you need, you can add to that list and calculate cost. Only thing is that you cannot mix the base Pizza options, but i don't think that's the requirement here. Am i thinking it wrong ?
I always wondered why "is-a" and "has-a" relationship between objects is even worth mentioning, but now I know just how important they are. It's amazing how a small detail like this can completely change the way we approach programming.
Glad to know that
I worked in both product and service industry of small, medium and large size company, i can see the clear understanding and explanation by the narrator on each of the topic and make an analogy to live code in my work. Very well explained in details, that too free of charge ,i recommend these videos to all the freshers or laterals who are working in java for upskilling.
Unbelievable that we are getting this video for free of cost.... Awesome explanation.
bhai ne kuch videos paid kr di 😁
Just can not believe that this piece of gem is free on youtube !!
Really appreciate your efforts. :)
Amazing concept, learning LLD is really an eye-opener. Thanks for this amazing video and explanation.
Thank you, pls do share it with your connections 😊
very good explanation is the best, simplicity is the base here and visual representation is toppings
Thanks Shrayansh for making these lld videos easier to understand. Apprepriate all your hard work.
Superb explanation. To recollect decorator pattern, I will remember the pizza example. Thanks a lot of this super useful video.
Welcome
Nice point : both isA and hasA property is needed! Awesome Explanation!
I can totally relate Decorator Design Pattern now, yestarday only i ate the 'PIZZA' now i'm learning and watching it. 😃✌
:)
'Has a' and 'is a' make concept much simpler to understand. Good point you make to explain.
Please dont make this channel paid ..it best channel in youtube at present time to understand lld concepts ...
Wish had explored your channel a bit earlier, awesome content on Low-level design(one-stop solution), Just feedback if you can arrange the videos of the playlist in what order to watch it will be really great for people.
Thank you Yash, not sure if youtube does not show playlist title and description, i have mentioned in both the place that Start from bottom and move Upward, let me check
Thanks for sorting it in "reverse" order. Glad that you considered the feedback. 😀
👍
Awesome explanation Sir. Thank you very much
Very good explanation with code...u did awesome job. really thanks a lot.
Thank you
The way you explain with examples it makes the concept very clear..Keep it up and thank you very much :)
Glad it helped!
🤯🤯🤯🤯🤯
Swaad hi agya 😋😋😋😛.
Thanks Shreyansh for this Amazing vedio series. Great content. And Beautifully explained.
Great content. First time i am feeling confident about LLD. Please share your knowledge more with us :)
Thanks there is a complete in depth playlist Manashi:)
@@ConceptandCoding Yes am checking. Thanks again for the content.
Nice video. You can add the main class with example of creation of these objects and using them that would help understand the concept better.
public class PizzaShop {
public static void main(String[] args) {
BasePizza base = new VegDelight();
System.out.println(base.cost());
BasePizza customPizza = new ExtraCheese(new Mushroom(new Farmhouse()));
System.out.println(customPizza.cost());
}
}
thoda nhi, bahut useful h bhai, please continue LLD series, you are one of best educators on UA-cam
thank you Prashant. means lot to me.
Thanks for the explanation with the examples.
Such awesome content, then its free. i cant explain how satisfied i am satisfied with your content. Thanks a lot bro. i have one request bro, whether you provide content free or paid, it does matter. just keep up. i have seen lots of videos and read books regarding design pattern. nobody explained like you. one thing makes your content unique, you deeply explain OOP concept behind design pattern.
Thanks Saifur
Bhai ek number i never imagined that i can also understand LLD. Every said that LLD and HLD is hard but now i feel i can also learn these concepts. Thanks bro and can you suggest the book that help me to learn HLD and LLD. It will be very helpful.❤❤
Thank you sir..today I start calling u sir..Thank you for ur efforts 🙏
Thanks a lot buddy but call me Shrayansh, we both are students,let's keep learning and sharing
this video is a GEM to the whole community, that too by a GEM..... hats off 2 u sir.. all this premium content for free , not possible on this whole planet itself,....
wish the java playlist would also become public / free someday , so that it can reach to every deserving candidate who cant afford the subscription at that point of time... s teachers like you are rare to find, your knowledge is uncomparable...
Thanks buddy
very useful very nice video
Awesome, simply awesome
Thank you
Thanks Shreyansh. Video is very helpful in understanding. I have implemented the same in python. Awesome initiative
Glad to hear that
I really understood this design pattern. thank you sir for wonderful explaination
thank you
I really appreciate your efforts thankyou so much😇😇😇😇👏👏👏👏👏
Thank you sir for another awesome video.
Thank t
J is silent in jalapeno😅. Rest video was awesome!!
Great job Shrayansh .
Great Explanation. Thanks for the video🙏
thank you
Great explanation. But I need to revisit the example once again.
Thanks for this playlist sir. Means a lot to us
Thank you
Very helpfull video
Awesome explanation
Thanks
LLD k members only videos mai jo questions hai like design parking lot etc unke code bhi included?
Very Well explained sir!
Amazing video Shrayansh!!
Thanks paji
mindblowing!!!!
Great work !
Great expansion 😃 ....
Thank you
Thank you Sir
How do we handle the case where 2 features are not compatible with each other? For eg. Say in car configurator, user selected both chrome grill and black grill, one of them has to be removed. First the user selects chrome grill so price increases by 100, then user selects black grill so first we have to reduce price by 100 which is for chrome grill, then we add 80 for the black grill.
Great Video , thanks a lot
Glad you liked it!
thanks for the video
2023 New Year Resolution -> Watching 1 video from Concept && Coding YT Channel everyday . Update -> Finished this 4th video in LLD Playlist today.
Hope you will find the content useful 🙏
Thank you so much for the detailed explanation :)
Very thanks
Super clear, I had a doubt: So according to this example "ExtraCheese" is a BasePizza due to indirect inheritance.
So in Vehicle example, the decorator would extend the BaseVehicle. Power Steering would inherit from decorator and in-directly have a "is-a" relationship with BaseVehicle, right
So in a way we are saying power-steering is a BaseVehicle so is it right? As power steering is not a Vehicle rather its a feature
Correct, if you want this pattern and design car with this way. Then you are right
Great explanation! :)
Thank you
Adding English subtitle would be really helpful for larger community.
Yes will work on old video, but all latest videos are in English only
Can we use interface instead of abstract class..I both in this case both will work fine
really thank you sir for your huge efforts, but sir, if we keep a final ingredients price Map in Base Pizza itself, and keep Topping Map containing topping and its frequency, this can be solved much simply for calculating the price, but then again that solution is not scalable ig when toppings list and price need to be updated, thanks again.
Awesome Explantion
Thank you
Awesome😍
Thanks
faad diya bhai
Another use case for this pattern is the avatar creation system in WhatsApp/FB
thanks for detailed video -- why BasePizza and ToppingDecorator in not defined as Interface ?
Could you please explain for the Pizza example, why not use builder pattern instead?
Maza Aagya
respect++
Thanks
Hi, Thanks for the great explanation. One small request could you please share the notes and the code that you are using for the explaination in each video. It would be beneficial.
Noted, will do it from now
//non decorator
BasePizza p= new Margherita();
Topping t1= new ExtraCheese();
Topping t2 = new Veggies();
Topping t3= new Paneer();
Topping t4= new mushroom();
string tot = updateDesc(p.desc(), t1.desc());
tot = updateDesc(tot, t2.desc());
tot = updateDesc(tot, t3.desc());
tot = updateDesc(tot, t4.desc());
updateDesc(total,desc){
return total+ desc
}
//decorator
BasePizza p= new Margherita();
p = new ExtraCheese(p)
p = new Veggies(p)
p = new Paneer(p)
p = new mushroom(p)
p.getdesc()
You should create video where you clearly stat the differences between "HAS- A" and "IS -A" relationship which will help many people
I think in 1 video i did that Vivek, if not then do check the first video of "Live LLD" playlist in that i must have explained it
Here is the timestamp ua-cam.com/video/-UjjfzJ574w/v-deo.html to understand "IS-A" and "HAS-A" relationship
please make a video on is-a and has-a concept with an example. Its very confusing.
You are awesomeee🔥🔥❤
Thank you
@@ConceptandCoding
Thank you so much for the amazing contents
Thank you
keep going :)
Please explain when to use decorator pattern and builder design pattern and differemces. Both seems similar.
One very important question sir ji, when to interfere and when to use abstract can u make a detailed video in this, i think this will solve many questions of LLD in a thinking way
When you want 100% abstraction go for interface, else go for Abstract class
Yes, i know this, but while in interview when we say that i will create an abstract class or interface or concrete class they always ask why so? Why not interface inplace of abstract class, this is has been asked alot.
So just a request when ever u make any any interface or abstract class please tell us the why interface or abstract please 🙏
Others : Learning Decorator Pattern from this Video
Meanwhile me -> Learning and Ordering a Margarita Pizza after watching 😂
:)
@ConceptandCoding Why do we we use abstract class here an not interface ?
why you used abstract class , can we use interfaces also ?
If i need 2* cheese 3* mushroom , how it can be achieved , instead of mutiple classes we can have db to store the details ?
Apne saraswatya mantra liya hua hai kya bro🥰
great!
I feel an improvment to this can be rather than creating concrete class for each topping create enum topping list class to dynamically update price for each topping
can you implement and show how for the same example which i took.
@@ConceptandCoding sure
from __future__ import annotations
from abc import ABC, abstractmethod
import enum
import string
from typing import List
class ToppingList(enum.Enum):
extra_cheese = 20.00
jalapeno = 30.00
mushroom = 10.00
chicken_tikka = 60.00
class BasePizza(ABC):
@abstractmethod
def get_ingregents(self) -> List:
pass
@abstractmethod
def cost(self) -> float:
pass
# concrete pizza class
class MargaritaPizza(BasePizza):
ingredients: List = ['Cheese','Bread','Olive Oil']
def get_ingregents(self) -> List:
return self.ingredients
def cost(self) -> float:
return 150.00
class VeggiePizza(BasePizza):
ingredients: List = ['Cheese','Bread','Olive Oil','Veggies']
def get_ingregents(self) -> List:
return self.ingredients
def cost(self) -> float:
return 200.00
class Topping(BasePizza):
_base_pizza: BasePizza = None
def __init__(self,base_pizza: BasePizza, topping:string) -> None:
self._base_pizza = base_pizza
self._topping = topping
def get_ingregents(self) -> List:
base_ingregents = self._base_pizza.get_ingregents()
base_ingregents.append(self._topping)
return base_ingregents
def cost(self) -> float:
return self._base_pizza.cost() + ToppingList[self._topping].value
if __name__ == '__main__':
base_pizza = MargaritaPizza()
margarita_pizza_extra_cheese = Topping(base_pizza,'extra_cheese')
print(margarita_pizza_extra_cheese.get_ingregents())
print(margarita_pizza_extra_cheese.cost())
margarita_pizza_extra_cheese_jalapeno = Topping(margarita_pizza_extra_cheese,'jalapeno')
print(margarita_pizza_extra_cheese_jalapeno.get_ingregents())
print(margarita_pizza_extra_cheese_jalapeno.cost())
@@ConceptandCoding Hey does the below solution follow any anti pattern wrt to decorator design pattern
this code still maintains 'is-a' and 'has-a' relationship. So that is the requirement of decorator pattern .
But here my concern with enum is not decorator pattern but with scalability and managebility lets say i want to add more methodd apart from Cost method like TotalCalories, totalProtein , totalCarbs etc. (lets say 10 -20 methods like this) how easy with enum to support this.
Thank you sir for this Amazing content. I have only one question that for every layer we have to create a new class so if our application will scale too much in that case we might have thousands of layers (Not specifically Pizza problem) so how can we solve that ?
Can you show the working demo as well. Need to understand how is main working. Based on input(order is magaretia plus extra cheese etc..)?
Strategy Pattern & Decorator seems alike to me like IStrategy even BasePizza Can have only HAS-A relation with ToppingDecorator or list (to calculate cost for all types of toppings) right. Please help me to understand the difference , By the way thanks for the videos :) #Concept&&Coding
I think main task of Strategy Pattern is to remove redundant code where as Decorator Pattern is used to solve the problem of maintainability of our classes.
Thanks for the great content!
Your videos are easy to understand.
Can we please reorder the videos in the order, currently its in reverse order and we have to play videos manually each time.
Thank you, sure let me check
Such a great content!:)
Thank you so much!
Thanks for the explaination. Really loving LLD. Used interface instead of abstract class for BasePizza and Toppings. Do you think there will be an issue in this approach?
Nope that's also good
what was the use of declaring the has a in toppings[ extraCheese] , are we using it some where?
Wonderfully explained!!
Its more like recurssion, so if imagine there are 100 of layes of decorator, then there might be overlapping subproblems. Can dp be used in that case?
i won't say its a Recursion, to me its looks like more of a hierarchy. Child-> Parent -> Parent ---> likewise
@@ConceptandCoding but a child might not replicate the same behaviouras that of parent.
@@BeyondTheFamiliar_2023 ummm Why not, in inheritance, child has its Parent capabilities+ additionally its own.
har jaga dsa ghusa do matlab
Let's say we have created a pizza object with 3 toppings, how do we backtrack to know which toppings and which base pizza was selected while storing in the db ?
Duplication in cheese and mushroom
❤
Hi, I understood this clearly, But I have a small doubt regarding Abstract class vs Interface. Can't we use Interface in BasePizza and ToppingDecorator, rather than using Abstract class? Other than this, I understood everything. Super explanation sir.
same question . Can anyone explain same @Concept && Coding - by Shrayansh
Firstly loving your videos! So thanks for that
Q. Is this really good to do something like new ExtraCheeze( new ExtraPanner(new FarmHousePizza())))...
B'coz not Basepizza object in ExtraCheese already contains a topping of ExtraPanner....
While if we were not to use Decorator design pattern... We would have had all the toppings on same level... (May be with a boolean flag)
It might matter if we don't want cheese on top of panner but panner and cheese mixed very well... (Sty could not think of a better example)
Why are we using ToppingDecorator? If we are anyways inheriting Extracheese then can't we inherit it directly from BasePizza as we aren't doing anything in ToppingDecorator class?
So here inheritance is only used for type matching and composition is used to get the behaviour.
It will give us flexibility in future
Can you explain why you used decorator abstract class in between rather than extending base pizza in ExtraCheese and ExtraMushroom classes?
had the same question
hey Shrayansh , i have one query in base abstract class why cannot we set quantity of toppings and calculate cost ?
I tried and understood and thought do I need abstract classes here cant I just use one Interface like BasePizza and implement it in my Base classes such as vegPizza and implement the same interface in topping classes but one chnage my topping class constructor should accept a BasePizza type Object;
BasePizza pizza = new Extracheese(new Margherita());
In my approach, I used an interface for defining a behavior and then created multiple concrete classes implementing this interface, each representing a different behavior. This seems somewhat similar to the Decorator Pattern, where each decorator wraps an object and adds its behavior.
However, I'm struggling to see a significant advantage of the Decorator Pattern over my approach in terms of scalability, flexibility, and maintainability, especially when considering the addition of new behaviors. In both cases, adding a new behavior seems to require just adding a new class without modifying existing ones. Could you help clarify the specific advantages of using the Decorator Pattern over this approach?
You have created A,B C different concrete classes. If you want to create new concrete classes with properties of lets say B , with decorator pattern you will have B1 , B2 etc. But without decorator pattern you might have to write more code to not only include the property of B but also its own new property.
I hope this helps.
Coming from a C++ background. Why did you use abstract class over interface here?
IN CPP
#include
using namespace std;
// Base class
class BasePizza {
public:
virtual int cost() const = 0; // Pure virtual function
virtual ~BasePizza() = default; // Virtual destructor for proper cleanup
};
// Concrete components
class Margherita : public BasePizza {
public:
int cost() const override {
return 100;
}
};
class VeggieDelight : public BasePizza {
public:
int cost() const override {
return 200;
}
};
// Base Decorator
class Toppings : public BasePizza {
protected:
BasePizza* basePizza;
public:
Toppings(BasePizza* base) : basePizza(base) {}
virtual ~Toppings() {
delete basePizza; // Ensure the base pizza object is deleted to prevent memory leaks
}
};
// Concrete Decorators
class ExtraCheese : public Toppings {
public:
ExtraCheese(BasePizza* base) : Toppings(base) {}
int cost() const override {
return basePizza->cost() + 20;
}
};
class Mushroom : public Toppings {
public:
Mushroom(BasePizza* base) : Toppings(base) {}
int cost() const override {
return basePizza->cost() + 40;
}
};
int main() {
// Creating a Margherita pizza with extra cheese
BasePizza* pizza = new ExtraCheese(new Margherita());
cout
Hi,
Suppose we have an abstract pizza class and an abstract toppings class which are inherited by concrete classes . Now, every pizza class has a list of toppings . So, when we calculate the cost, we just iterate over that list and compute the total cost. I have a big doubt that if only has-a relationship is solving this problem. Why do we need such a complex structure of has-a and is-a relationship existing at the same time and what extra advantage does decorator pattern bring into picture ?Looking forward to your reply to this question.
okay, could you please tell me, how you would solve the scenario where you have 1000s of combination like
BasePizze,
BasePizze + cheese ,
BasePizza + mushroom,
Veggie + cheese and go on......
The biggest advantage decorator pattern adds up is control on number of classes if there are so so many combinations possible.
@@ConceptandCoding Thanks for your reply.
Lets suppose Base pizza is extended by two Pizza class Veg and Non Veg Pizza. I have another ExtraAddOn class which is inherited by say cheese, mushroom, paneer and so on ...
Now, I have a " vector extraList; " in Veg and Non Veg Pizza class.
So, whatever combinations of ExtraAddOn you need, you can add to that list and calculate cost.
Only thing is that you cannot mix the base Pizza options, but i don't think that's the requirement here. Am i thinking it wrong ?