Java 8 Lambda Basics 21 - Method References

[@praveenkumargupta4480]

Hello Sir, Please prepare another course for advance lambda and streams.This basic lambda course is awesome just because you serve it like piece of cake. You have great and unique tactic of teaching.:)

[@aviet90]

Yes please

[@paraschawla3757]

@Java Brains - Please include Collections and other advanced lambda concepts in 2.0 course. Couldn't find any other resource where same has been explained so succinctly.

[@hiepxuan2008]

Please create courses on other topics as well; even you sold it, we are here to be ready to buy it.

[@arpitj795]

There is not better place to learn Java and its features than this Guy's tutorials. Koushik sir Please make more Java Specific courses, because like me hundreds of thousands of youngsters are relying on you.

[@moseswilfred6497]

This is the best ever course on introduction to lambda that I have seen. Looking forward to the advanced lambda course.

[@amitcool99]

I have completed several of your courses! This course like the previous courses is well designed, well prepared and easy to follow. Thank you very much for putting a lot of effort into creating quality content.

[@hussamselim9676]

your Lambda Basics playlist is one of the best, I sent it to my entire university to watch...thank you!

[@manishsrms]

Sir, I told about your channels to many of my friends. All are happy after knowing about such wonderful channel. All credit goes to you.

[@carlmarks2199]

MORE! MORE! MORE! WE WANT MORE!!

[@Gan918]

Simply the best tutorial of Lambda, even a novice person could understand, please add more

[@shimonarudra8763]

Hi Koushik, your skills as an educator are unmatched. The content is crisp, the flow of the course is well designed and you explain complex concepts with such ease. Your videos are my go to for any new concepts that I want to wrap my head around. Request you for more videos on advanced lambdas, spring mvc and concurrency in standalone and webapplications. Thanks a lot and keep it coming!

[@nagaraju2083]

Hi Sir, you are not a tutor. you are an easy life maker. thank you soooooo much, waiting for Advance Lambda.

[@rafalo2323]

Hello Sir, thank you for your work, please prepare advance lambda

[@ganeshrajput005]

Very nicely explained the concepts of Java Lambdas. Recommended to all Java coders.

[@viveksingh195]

Nice Tutorial - I Love watching your tutorials, they provide clear cut concepts.

[@bijanzohouri98]

Clear Explanation on Lambda expressions and Collections as well as the other features in Java 8. Besides, the videos are really fairly short so that, you don't have to spend much time on unnecessary points . Good Job

[@foruvasanth]

@8:20 out is still a static member i believe otherwise how we are referring it using System.out where System is name of the class. Question is :: is applicable only to static members or any

[@mirazimi]

Advanced Lamda course please! Also one on Java 8 advanced Generics would be wonderful. You’re a gifted teacher.

[@utkarshsrivastava1079]

Excellent course !! Never understood lambdas better.

[@raghavaprince2907]

Please provide more advanced lambda expressions.. Here is the place Where I learned java and became a java developer in 2015.Very good explanation and easy way to learn.

[@RanjithKumar-xh8oz]

Best tutorials i have ever found

[@gkcotech7211]

Thank you, the best part of the tutorial is , its really very concise and to the point.. I will gradually watch your rest of the tutorials.. :)

[@dheerajsaini9955]

Thanks!

[@hyperborean72]

For me personally the more implicit code we have ("How does the compiler knows that? " - Oh, Gosh) the more irritating it gets actually. You have to look carefully around to understand what is explicitly missing in this or that declaration

[@soundhermm5514]

This Lambda basic course is awesome. Waiting for your advanced course in lambda

[@Akki22101988]

Sir.. The way you have explained the lambda expression concepts is really amazing. Please introduce more courses on Java.

[@sureshb8869]

Hi Sir, Please prepare advanced lambda for collections.most of the people are waiting

[@sambarapu100]

Nice Clear Explanation !! was wondering about lamdas and you made it easy for me .. looking forward for more videos. Thanks

[@bibhachaurasia7886]

Really great explanation Koushik. Its very easy to understand and most of my doubts got cleared. Please upload advance videos on Lambdas and stream APIs, many of them will be benefited. Thanks a lot for sharing videos.

[@ro13ert66]

Really excellent work! I have one question about this method references. Say if I want to print more than just the parameter that parsed in, how can I do this using method references? For example, if I want to add some words before the parsed parameter such as System.out.println("The value is: " + param); , can I do it with method references while not wrapping things up?

[@priyankawagh5217]

please provide the advance course using collections and stream api! you r awesome teacher.

[@utopianguy]

How does the compiler know what is the passing argument for the method reference?

[@shahabyounas]

Interactive tutorial Looking forward Advance Lambda Expression Course, Java9 and Advance Spring Boot. Thank you java brain.

[@Natsu_Morocco]

I like your courses alot so please go ahead :)

[@manjeshk11]

I do really like this series very useful, so it will be grateful if you make Java 8 series also

[@premv6904]

Thanks for such fine tutorials, the concepts were crisp and clear.

[@shubhamchouksey9904]

Is using Method References a good practice for maintainable code? I see that the reader has to actually look into the parameters of the and keep both of them side by side.

[@aryashrestha6601]

sir can we have advance lambda tutorial. too. the basic were awesomely taught.

[@jeromejj1481]

Hey Genius! You knock me dead just like that. Hat's off to you for your selfless initiative. Gratified abundantly as your ardent follower. Keep up the good work.

[@0001adarsh]

You are awesome. Such great technique to explaining concepts. Also do make videos on Completable Future.

[@MyHemadri]

Very nice and fantastic explanation.... you are java GOD!!!!!

[@hamsalekhavenkatesh3440]

wow, awesome sir ..GAVE ME A CLEAR picture of lamdas!! please make an advanced video on this...and kudos to ur effort u explain complex topics very clearly and in east to follow up way

[@MrRicharddaniel]

Please Advanced Lambda Please :) You are one my fav teachers here on youtube

[@vinodgharge7225]

Hi Sir, please prepare advance lambda course.... Much needed...

[@brianocorner5604]

Hi!.. I was trying to use method reference for printing a message e.g. System.out.println("Hello") as System.out::println("Hello"). But I was getting compile time error, Can you please explain it why and how it internally works?

[@rokkistart]

This course is really new level for me ))) I'm exited))

[@amirthasaha]

Thank you sir for such wonderful courses, cant thank you enough for making it very simple and interesting. Can you please make courses on basic java so that it would be of great use for beginners in Java. Thanks again! I have gone through almost all of your courses and it is mind blowing.

[@TheKNdheeraj0]

How can I use System.out::println to print only First Name or Last Name because using System.out::println prints the entire data of the list??

[@ajayyaatri]

Great tutorial.. Man you should do more of this.. hats off to u !!

[@nitantjoshi8614]

Sir, please create a detail videos in java streams. This series is really helfull.

[@sivashankar1850]

nice carry on with lambda's in depth sir

[@vimalbs]

Please create a course for Collections

[@shakthiandmaheshwari]

Hello a question pls..why would you say the "out" object in System class is instance, isnt that a static member of the System class?

[@shakthiandmaheshwari]

sorry i later understood u meant println is an instance method on out.

[@onlinetvoffical]

Awesome videos! Please prepare advance lambda

[@amithballolli2598]

Hi sir, thank you for such a great course,please do a course on advance lambda

[@vinuthat1858]

Looking forward for more topics in java 8 and 9

[@orz5516]

are you planning to make more java courses?

[@IsaacKamga]

We kindly await a course on Advanced Lambdas

[@entertainment55]

please create a course on advance lambda's

[@monikajha3500]

I feel I have missed so many things even if I miss just one video from Koushik :)

[@balkrushnawagh2641]

hello sir, please post the tutorials for advanced lambda with collections and streams in detail.

[@rohitgovindugari]

Make a course for advanced lambdas

[@wattheshet]

You know if you have a course on udemy about advance java stuff. I will definitely buy it. You explain really well

[@MrGauravmatta]

Is this only possible with Static Methods?

[@hemantk611]

No..its also possible with instance method as well. We have to create object then using object reference we can pass ...

[@ravidongapure3164]

Please!!Pleaase make tutorial on advance Lamda

[@tejassabunkar9079]

Sir, Please Prepare more advanced course we will love to intake more concepts from you.

[@AryanSingh-fu2cf]

Sir, please create more tutorials on lambda....

[@deepthinker1710]

this is the most difficult topic in my life.iam still confused

[@GihanKavinda.]

me too

[@sahilsehgal626]

Hi sir, Can you please start the course on advance lambdas. Please sir... :)

[@zerziszain]

But WHY we need method references? What was the problem with using lambdas? Why to introduce one more way to do the same thing? Doesn't it actually add to the complexity of the language? Unless there is some benefit. So why method references? What they can do that lambdas or any other java's feature can't?

[@LeeHongYee99]

Saurabh Patil i.also feel the same way

[@georgetsiklauri]

Several major mistakes and wrongly explained points here: 1. out is not and has never been an instance field/variable of System class; (moreover, you are simply unable to invoke/call/access an instance field/method, via period symbol.. basics of Java). You are mentioning several times, that it's an instance, but it's a very static field; 2. Talking about the numbers of arguments/parameters of the lambda expression, in the "Method Reference" topic's context is also very misguiding and confusing. Actually, one might get something working and might think, that he/she understood this correctly.. but it's not about one or two arguments only. What if you'll have (s, t, k, z,) -> someMethod(s, t, k, z) ? can't you use a reference of the method here? well, despite all respect, this is a very wrong approach; the point of Method References is: 3. .. that you are matching the signature of the existing (implemented) method, to the signature of the Functional Interface (Lambda's type), and if they match, you can assign a method, as a value, to the Functional Interface type's variable, so that after you call a method on that variable, referenced method will be executed. If you have interface Operable { void doSomething(int a, int b);} and somewhere else a method - public void sum(int a, int b);, you can assign this method's reference to the variable and use that variable anywhere code expects the respective signature of the method. forEach(System.out::println()); works because, of forEach expects the lambda of type Consumer, and System.out.println turns out to be a type of Consumer, since it accepts T and returns void; 4. The only difference between using Method Reference in either static or instance methods, is the new keyword. You use instance method's reference as "new CustomType()::methodName" and you use static method's reference as CustomType::methodName".

[@NeverGiveUpTryin]

I agree with you and would like to understand more on your 3rd point. To test I'm using a Consumer and trying to print a string using method reference. //case1. Consumer con1 = System.out::println; con1.accept("Hello"); //prints Hello Here, the println(String) method from PrintStream matches to the method signature of accept(T) in Consumer and so it works fine. Understood. //case2. Consumer con2 = System.out::printf; con2.accept("World"); //prints World Here, I'm using printf method from PrintStream which either takes 2 or 3 args and also returns PrintStream. This doesn't match to the method signature of accept(T) method in Consumer, as accept(T) method accepts only 1 arg and also returns void. So how is it still able to print the value ? Why the compiler doesn't complain ? //Case3. Consumer con3 = System.out::printf; //compilation fails because printf does not have any version that accepts an Integer. con3.accept(100); My understanding is, printf method has 2 overloaded version printf(String, Object) and printf(Local,String,Object) in PrintStream class. Now when we create a Consumer and assign System.out::printf to it, the compiler checks if a string can actually be passed to printf method. Yes it can be and so for other arguments, i guess it passes null. May be I'm wrong.

[@vishank848848]

best tutorials sir, please make same on advance lambda...thanks in advance...........

[@Dyslexic_Neuron]

plz make multithreading series !!

[@GihanKavinda.]

I can't get it, method references is harrrd : (

[@chirangaalwis4014]

Hopefully new tutorials on new Collections improvements

[@AmineC88]

please prepare advance lambda tutorials

[@IamAWESOME3980]

What a misuse of the c and c++ scope resolution operator.

[@manishsrms]

We want more Sir... More Pls more..

[@amandeeptomar1772]

really awesome course

[@emrekaplan742]

amazing vid!! thanks

[@rbelatamas]

Thank you very much!

[@shashikantkamble5406]

Advanced Lamda and Java 8 Please!

[@MrJamesJ133]

Thank you so much bro , please help me in understanding lambda with collections in detail. Please Please. :)

[@jaswanthnanda8122]

best tutorials

[@christinal7041]

Thank You Very Much! Please find time to teach advance Lambda!

[@aruljazz9774]

Hello SIr, Please allow the JAVA and java interview video to be free. Because lot people are looking for your version java video. So please make that as free one.

[@vatsalmehta6644]

Think this method references are making code less readable!

[@tripsikkim8398]

its an alternative however sounds weird

[@nandini.nelson]

Looks like c++

[@muditjain6975]

Great

[@satyas3136]

Awesome video, but no doubt why java is lagging behind Python, when python is bringing new API wrt AI , ML , DS java is focussing on this nonsense stuff of rewriting same stuff in different way. This is annoying.

[@Standupibrahimbackup]

Guys if you find any concept of lambdas hard just remember, lambdas are nothing but functions. Replace Lambdas with functions and everything will be easy as stealing candy from a baby or as easy as my ex cheated on me :)