Immutable Class - interview insights| java interview questions and answers for experienced/Freshers
ฝัง
- เผยแพร่เมื่อ 20 ก.ค. 2024
- Let’s learn different techniques to protect our custom immutable class in java which is one of the hot core java interview questions. In this video, we will start from absolute scratch, i.e by creating a mutable class and understanding different loopholes of a mutable class.
Then we will convert our mutable class to immutable and will understand how to create immutable classes in java. While creating custom immutable classes, we have
take care of various scenarios, which are some top core java interview questions.
Some top 10 java interview questions for this topic could be :
What is a mutable class?
How to create a custom immutable class?
Why the immutable classes are final?
Why Immutable classes don’t have any setter?
How to protect your immutable classes if your class got some mutable objects reference?
Why the hashmap keys are immutable?
few of the questions from the above and some more questions we will discuss in the next video.
Make sure these questions come under java interview questions and answers for experienced and java interview questions and answers for freshers category. So whether you got some experience or you are fresher; you can expect this java immutable vs mutable topic ( as java interview programs) in your java job interview.
Time stamp:
introduction : 00:00
Immutable object definition : 01:25
What is a mutable object? : 02:53
Mutable Vs Immutable : 06:16
Custom Immutable class : 06:58
Mutable reference inside Immutable class : 15:03
breaking java immutable classes: 21:27
Protecting your immutable class (code fix) : 24:50
hashcode() comparison: 35:15
Important scenario based interview question : 39:10
Using copy constructor : 45:00
Using getInstance() method: 49:09
Pros of Immutable class : 52:13
Uses of immutable classes : 56:24
for more java interview questions / java interview questions and answers for experienced /java interview questions and answers for freshers, consider subscribing to my channel.
/ @seleniumexpress
#CoreJavaInterviewQuestion #FAQForfreshers #FAQForExperienced
More core java interview questions :
Why String is immutable?
• Why string is immutabl...
String Hashcode caching internal. Hashcode caching for immutable classes (important)
• This is why string is ...
Why hashmap works internally?
• How HashMap works inte...
java interview questions and answers for experienced / Freshers [playlist]
• TOP 6 difference betwe...
For more courses visit
www.seleniumexpress.com
Any time you are getting stuck with issues, Feel free to ask for support.
You can send mail to seleniumexpress@gmail.com
you can ping me on my Facebook page
/ seleniumexpress
Make sure to join my private Facebook page (Ask me here)
“SeleniumExpress - Support”
/ 187000222361579
you can ask for support in my website forum
www.seleniumexpress.com
Follow me on Insta
/ selenium_express
Music :
-----
credits : -
(channel intro)
Adventures by A Himitsu / a-himitsu
Creative Commons - Attribution 3.0 Unported- CC BY 3.0
creativecommons.org/licenses/b...
Music released by Argofox • A Himitsu - Adventures...
Music provided by Audio Library • Adventures - A Himitsu...
Hey Abhilash! The day I watched this video just after receiving your channel update, the very next day I had my interview and guess what the interviewer asked me this particular question and he had given me the exact same example (every bit was similar) and I also gave him the same explanation and guess what I cleared that round. The moment I heard this question I was like thank you , thank you Abhilash for this video, it saved one of my opportunities. You are fab man! Thanks a ton :) Keep teaching, I will keep learning :) Bless you
Congrats, Pranoti ! 😊
Just randomly watched this video and ended up liking and subscribing the channel.
It's so good to see that you guys are contributing so much in training and educating the developer's community.
Lovely explanation! But still there is a catch which can break this I think : in student constructor you are directly assigning adress ex : this.address = address;
It's should be something like this.addres = new Address ( adress.city , adress.state, adress.country) .
Because when you created adress in main method , you still know that refrence . So alway clone before assigning in constructor
You are doing awesome Job, I have literally cracked interviews of many companies by watching your Spring concepts, thanks so much for your valuabe teaching,also please if possible create video for microservices with spring boot also.
Your teaching like feed with spoon for students, The best lecturer in TH-cam, he must get more subscribers !!!!!!
Clean... Clear... Crisp.... This is one of the best explanation i ever heard. Kudos to you all.
Your video defines how much effort you have puted when you have learnt this concepts
I went to your website and saw Spring boot course and it costs 15000 !!!!
Why man why.. U r the best trainer for me .. Everyone can't offord such high price course. I request u to add your course in udemy with much less cost. ☺🙂
Great to have you back Sir. Eagerly waiting for the follow-up video. 👍🏼
again watching this video literally so great informative video..
superb, i wasn't aware of so many other possibilities, Thanku so much. definitely it will be very helpful in the interviews & thanks for sharing the real time approach also as it wouldn't be a new thing in future coj of your informative videos. Really each & every aspect is covered.
Brother im completely impressed. I never understand this topic before like that
Sir, I am very helpful and lucky that i am able to learn n understand Java / spring by your uploaded youtube video. I request you to provide spring boot and spring microservice video tutorial in upcoming days asap. please...!
Increasing confidence on java.. Thank you 😍
Damn man once you start watching his videos there is no go back ♥️
Happy to see after longdays
Clear and Crisp Explanation Abhilash. Thanks for sharing.
Abhilash I got selected just watching your tutorials. THANKS A LOT TON CRORE...subscriber 🙏
Amazing video, Abhilash.
Great explanations....really helpful for interview
One of best video on Immutable class
Is been a while. Good to here from you.
Hi Mr Abhilash i miss you soo much. I miss also your videos. You are the best teach in youtube you must know that.
very well explained sir.Thank you for this video.
Hi Abhi,
The point you mentioned during explanation of advantages of Immutable objects - "thread safety is guaranteed because data inconsistency is avoided in a multi-threaded environment".
How can data inconsistency arise for a immutable object when it cannot be modified in the first place? or did I miss something?
Hi Abhilash Thnaks for this video, that's very great each and exery step explained well, can you please make one video on complete Data JPA
Nicely explained....I have one double ,what is the use of making the class final as already all the data members are final ,no setter method, get method is not returning the original object.
Love u bro... u r a motivation an inspiration... the reason i started finding interest in coding
❤❤
Very Nice Explanation!!
I have a question, what if the Address object that is being used to pass to the Student class constructor is manipulated. The method, where we are creating the Address object has the reference to it. Now though the student object cannot be used to manipulate Address, but the address reference can still manipulate the Address Object inside the Student Object. I think we should clone the passed Address Object as well and then assign it to the Student address member.
You deserve a beer bro...superb explanation 💪💪
This was really helpful content. Thanks Abhilash
Hi Abhilash, it's very clear and nice video. I have doubt can we give clone object of addres obj in the get method of student instead copy constructor. As implementing colnable interface in address class
Big thanks man. Way of teaching is great.
Simply awesome
Could you please upload Java core videos (I am very excited to learn the fundamentals from you. You are covering the in-depth knowledge which on one covered in my knowledge so far..)
Abhi, try to add more live interview..it's interesting to watch and helpful that how to present during interview. Nice explanation.
Hi Abhilash, In this Student Class constructor, i think we need this.addr = new Address(addr.city,addr.state); this statement instead of directly assigning the reference like this this.addr = addr i hope this is the correct way.correct me if it is wrong.
Thanks Abhilash ☺️
good explanation. thanks.
💫
Thank u so much!
Amazing explaination
Good stuff
super..
Quality content 🔥🔥
Very nice quations
Hi sir finally I got job in mnc company after seeing your videos so many thanks to you
Congratulations 🎊 All the best !!
Great stuff 🙂
Appreciate your teaching ways with explanation but if you make it within 10 minutes video not 40, 50 minutes for a small topic. That would be great for learner otherwise will skip
Hi Abhilash
Can you take concurrency Concepts in Java and make videos?
Hey
in which video have you explained why to declare immutable class as final?
please link it
Everything is good Abhilash the only thing I wanted to say, some portion of the video is a little exaggerated which is not required, the video could have been a little short.
can you make a vedio of spring mvc with firebase push notification.
❤❤❤
hi brother, plz make the video in ......."debugging concepts" .....in java
pls upload the video for spring boot snd microservices
Hi @Selenium Express,
is the below code too violation of immutable class. If yes, please help in correcting.
Address address = new Address("MAA", "Tamil Nadu");
Student student = new Student("Me", 20, address);
System.out.println(student);
address.setCity("BLR");
address.setState("Karnataka");
System.out.println(student);
I think one scenario is missing. If I have list object, how will you deal with that? This scenario should be covered.
Abilas we waiting for spring boot course over 1 year, and now we must to pay. That course is most important to us for job.
A tip: you can watch series on flixzone. I've been using them for watching lots of of movies lately.
@Nico Lucian Yup, been watching on Flixzone for since november myself :D
Hi
I have one query:
Can we create a duplicate object of the immutable class using serializable or reflection API?
s
Student1 s=new Student1(1, "gayathri");
System.out.println(s);
s=new Student1(2,"devi");
System.out.println(s);
with this the values we can change right even though the variables are final
Waiting for spring boot microservices video
but what if we change the content of Address class object using homeAddress object here we are creating separate copy so it works as expected.
try this example:
Address homeAddress=new Address("delhi", "Delhi", "India");
ImmutableClasses ic=new ImmutableClasses(1,"Aashish",homeAddress);
System.out.println(ic+" "+ic.hashCode());
homeAddress.setCity("Kotdwar");
homeAddress.setState("Uttarakhand");
System.out.println(ic+" "+ic.hashCode());
Rest everything is fine we can add below lines to the constructor of Immtable class->
public ImmutableClasses(int id, String name,Address address) {
this.id = id;
this.name = name;
Address clone=new Address(address);
this.address=clone;
}
it will change the content of homeAddress object. @selenium express please correct me if i am wrong.
Please give me a favor i need to learn spring boot can you post some videos about it. Sorry for my English
So you will be creating new object for each get method. Is this a correct approach
You missed FINAL keyword before class consequences
Is that penny from big bang theory
When is the next session??
Hey Abhilash! You really have put on some weight.😂
😅
Your example has 1 bug. If you do any changes in homeAdress object then it will break immutable class concept. Don't take it otherwise. I have been learning very good concepts from your videos
Yes. To fix this, you need to change the student constructor
I used cloning for address object
In Address class, implement Clonable and add clone method. @Override protected Address clone(){return new Address(this.city,this.state,this.country); }
And in Student constructor
public Student(int id, String name, Address address) {this.id = id; this.name = name; this.address = address.clone(); }
Isn't this kind of copying things called "defensive programming"?! Correct me if i'm wrong
You put on weight u were good when u was lean🤣
Your knowledge directly proportional to weight
😂😂
Boss sorry but your videos are too lengthy, really difficult to watch such a long video for small topics..
Why are u repeating the same thing too many times and wasting our time. It's a 10 min video. Bro Better don't do videos seriously frustrating and wasting time by repeating
pahle toh apna pronunciation correct karo...Please dont try to sound like foreigner .Be you ,be original
Hi Himanshu ! Thank you for taking time and writing a feedback.🙂
Hi Abhilash,
Very impressive explanation :)
But I have a doubt - Immutability means " Once an object is initialized, we are not allowed to change its content(value). And when we try to change its content, if there is any change in the content then new object will be created, if there is no change in the content then the original object should be returned" . Just given String behavior example below....
package com.corejava.string;
public class StringTest {
public static void main(String[] args) {
String str1 = new String("Murali");
String str2 = new String("Murali");
String str3 = new String("Murali Tekumatla");
String str4 = str1.replace('M', 'M');
String str5 = str1.replace('M', 'T');
System.out.println("str1 ======" + str1 + "=======" + str1.hashCode());
System.out.println("str2 ======" + str2 + "=======" + str2.hashCode());
System.out.println("str3 ======" + str3 + "=======" + str3.hashCode());
System.out.println("str4 ======" + str4 + "=======" + str4.hashCode());
System.out.println("str5 ======" + str5 + "=======" + str5.hashCode());
System.out.println("str1 ======" + str1 + "=======" + str1.hashCode());
}
}
Output:
str1 ======Murali=======-1978977868
str2 ======Murali=======-1978977868
str3 ======Murali Tekumatla=======1155040398
str4 ======Murali=======-1978977868
str5 ======Turali=======-1778573811
str1 ======Murali=======-1978977868
1. In above example, str1 created.
2. str2 object created with same content hence it return original object as hashcode is same as str1.
3. str3 created with differenct content hence new obj is created with diff hashcode.
4. str4 - trying replace char 'M' with 'M', no content change hence original obj is returned.
5. str5 - trying replace char 'M' with 'T', content change is there hence new obj is created.
I think we are missing this behavior in our Student-Address example in this video - can you please comment on this.
- Thanks