Java is pass/call by value or pass/call by reference [MOST IMP. JAVA INTERVIEW QUESTION]| ode Decode

[@shubhamtagalpallewar7125]

Thank you ma'am, I have been asked this question in interview and I was unable to answer properly, now I am confident on this topic.

[@CodeDecode]

M glad that you are. :) May you reach all the heights in your career

[@nndsmsjsjs2501]

@@CodeDecode mam pass By Value Means Call by value Right?

[@Neerajkushwaha-uz8wo]

Us😄

[@sravyayerrams]

Pass By Reference: Changing the value of the real address in the memory. Pass By Value: Copying the value to another location and so the real value is not changed.(java)

[@CodeDecode]

👍👍

[@amitjoshi940]

Java 8 : pass by value or pass by reference

[@dheebanm3207]

Real time example is very easy to understand, thank you...

[@CodeDecode]

Thanks Dheepu 👍

[@vigneshramesh7691]

With the Last example all the doubts are cleared that Java is pass by value. "Just passing a reference as value. " 8:12 - 8:16

[@CodeDecode]

👍👍m glad you understood this so clearly 👍 appreciable

[@roobanraj28]

Thanks for this crystal Clear Explanantion .

[@CodeDecode]

👍🙂

[@renejacques8288]

Clear explanation. I hope that'll help not to forget it again.

[@CodeDecode]

Thanks 👍. Yes hopefully 😊

[@TheMilinmodi]

Thank you so much mam. Much clear till you convinced that java is pass by value but when you explained with java object then it becomes confusing. Please explain in detail for when we are changing the value using object. Also, Congratulations to you for new subscriber as well. Gone thru channel and found it very helpful.

[@CodeDecode]

Sure we will create a more clarity video on this. Thanks 👍

[@avinashkumargond3291]

Last wala example related to refreneces, was really osm

[@abhivela]

The topics you cover here are so unique !!! I have seen many tutorials for Java..... But the type of topics you cover here and the explanation is top notch!!! ❤ Thank you for your efforts 🎉❤

[@CodeDecode]

Thanks Abhi 😊👍

[@anurani7084]

Thankyou mam.. for explaning this in a wonderful way

[@secretsociety2510]

This is very helpful video. Thanks a lot for explaining this👍

[@CodeDecode]

Thanks Amogh for the nice words....

[@dhananajaykrishna8259]

Simple and clear explanation. Aweesome!!

[@CodeDecode]

Thanks 👍

[@WAQASAHMAD-cw1ds]

Thank you so much Ma'm to clearing my Concept... & Congratulations for a new subscriber 😉

[@CodeDecode]

Thanks Waqas 👍👍

[@Asadullah-bg5ny]

what a brilliant way of explaining , finally got the answer.

[@CodeDecode]

Thanks 🙃

[@gsathyanarayana7366]

Thank You for making this video. Need small clarification, when primitive variable 'a' passed as an argument to a method you said java copies the value of 'a' to a new memory location and that location address passed to that method as argument so value wouldn't update in parent class ? Same theory isn't applicable to objects ? Java doesn't copy the object to different memory location and sends that memory location address to method as an argument ?

[@abduldaniq5004]

Exactly I got that same doubt

[@nrusinghacharya]

The problem you're facing here is statements like In Java, Objects are passed by reference, and primitives are passed by value. This is half incorrect. Everyone can easily agree that primitives are passed by value; there's no such thing in Java as a pointer/reference to a primitive. However, Objects are not passed by reference. A correct statement would be Object references are passed by value.

[@shiva3895]

@code_decode small question. If java is pass by value & values is passed after copying it. That means object reference value should also be copied first and than passed. If Yes, a memory address is being copied and that is my missconcecpt. Can you please explain. Thanks!

[@singhji4149]

Great explanation 👌🙏

[@CodeDecode]

Thanks

[@siddheshtoraskar9537]

Great explanation with nice example 👍🏻

[@CodeDecode]

Thanks 👍

[@nagar4u]

Good content. Keep growing. Keep it up.

[@CodeDecode]

Thanks 👍

[@SaratKumar-qk7lu]

Good to see this channel.

[@CodeDecode]

M glad you liked it

[@nivassimhadri2229]

seen many videos from your channel, everything is on point explanation and also the slides are perfect to read even though there is no audio. where can we find all your presentation slides?

[@CodeDecode]

Thanks a ton Nivas 🙂👍

[@prudhvinadh5786]

Nice explanation

[@CodeDecode]

Thanks 😊👍

[@sanketh768]

Thanks mam, please continue to make videos like these to help people. Maybe after java sometother topic like database

[@CodeDecode]

Yes, definitely

[@gargijoshi5186]

Best explanation by far

[@CodeDecode]

Thanks Gargi

[@satyamshah9164]

Very clear explanation mam!

[@CodeDecode]

Thanks :)

[@navneettripathi2110]

Commenting for the 3rd time....for comparable comparator detailed video...

[@CodeDecode]

. Sorry for keeping your topic on hold. I needed to cover basics first for that video. Now since we have covered most of the basics we can take that topic now.

[@CodeDecode]

@navneet All you need to know about comparable and comparator Please like and subscribe. kzbin.info/aero/PLyHJZXNdCXscG1g50RaLZdXgBhC-C7dCy

[@jeeteshkumar11]

Great explanation

[@CodeDecode]

Thanks 👍

[@sabbaticalcountdown]

You did an excellent job explaining, thank you so much!! =)

[@CodeDecode]

You are Welcome ....

[@abhishekarya8108]

Nice explanation!

[@CodeDecode]

Thanks abhishek

[@tapanparida3176]

God bless you mam for your good work…your work really helps people….keep up!!!

[@CodeDecode]

Thanks a lot Tapan 🙂👍

[@sanketh768]

nice explanation however had a doubt, since java is pass by reference for object as per your example for Animal Object. i tried the same example with Integer since its an Object, the same was not happening. Please check the below example. public static void main(String[] args) { Integer i = 10; change(i); System.out.println("main"+i);//op is 10 } public static void change(Integer i) { i =11; System.out.println("method"+i);//op is 11 }

[@thivagarmurugan2955]

u creating primitive datatypes in main function and u just passing copy of i in change method so any changes made in change only affected in change alone not in main method the both different

[@niteshbhati6496]

It is because all primitive wrapper classes (Integer, Byte, Long, Float, Double, Character, Boolean, and Short) are immutable in Java

[@Dharmik_Vibes]

primitive wrapper classes in Java (such as Integer, Double, Character, Boolean, Long, Short, Byte, and Float) are immutable. Explanation: An immutable object is an object whose state cannot be modified after it is created. In the case of primitive wrapper classes in Java, once an instance of a wrapper class is created, its value cannot be changed.

[@kasiyedumati9423]

Awesome explanation

[@CodeDecode]

Thanks 👍👍

[@saikumargoud3257]

Thank you mam I had understand very clearly but one doubt raised in mind that why java is particularly called pass by value here we are doing both pass by value and pass by reference can you please explain mam?

[@vigneshgvs]

chatgpt gave below sample on justification: In Java, you always pass the value of the reference to an object when you pass it to a method. This means you are passing a copy of the reference, not the actual object. Java itself does not provide a way to pass the actual object by reference as some other languages might. Even when you pass an object as a method parameter, you're still passing a copy of the reference to that object. (kindda pass by value). However, the confusion often arises because operations on the object itself (like modifying its fields) are visible outside the method, giving the appearance that the object is being passed by reference. class Person { String name; Person(String name) { this.name = name; } } public class Main { public static void modifyReference(Person person) { person = new Person("John"); // This reassigns the reference locally, not affecting the original reference. } public static void modifyObjectFields(Person person) { person.name = "Jane"; // This modifies the actual object, affecting the original object. } public static void main(String[] args) { Person person = new Person("Alice"); modifyReference(person); System.out.println(person.name); // Output: Alice modifyObjectFields(person); System.out.println(person.name); // Output: Jane } }

[@akah2]

Excellent

[@CodeDecode]

thanks

[@pankajchandel1000]

Best explanation !

[@CodeDecode]

Thanks sanjay

[@alfiyakhan4580]

Ma'am I am having a doubt, starting 4 mins of the video where you said "to access a private method you have to make it static", I didn't get that point. Please explain.

[@veerannajakkula]

Good explanation. Thank You. You can also pass any list to a method and update the list in called method to provide more in-depth analysis.

[@CodeDecode]

Sure 👍

[@drashtinaik5751]

It is perfect explanation. But still, can you please add new video on this with detail explanation and example.

[@CodeDecode]

Sure Drashti, what do u want us to cover in that?

[@drashtinaik5751]

@@CodeDecode In detail with heap and stack memory allocation that will give much clarity .

[@drashtinaik5751]

@@CodeDecode And thank you for fastest reply.

[@CodeDecode]

Sure. You need Java memory management. Right?

[@CodeDecode]

No worries 😊😊

[@commenter9451]

Best explanation ❤️

[@CodeDecode]

Thanks

[@abhishekganguly165]

Hi mam, In 1:18- 1:21 aapne kaha ki "we are changing the value at the real address in the memory" this is pass by referance. and that is what is happening in your last example. when you passes a value the it is changing its value. If you are passing a referance, then the address of the object is getting copied, and it is changing the value inside that object. So can you Please expain me in details for call by referance with a heap and stack memory representation. if possible.

[@abhishekganguly165]

I got it first in google search that: Pass-by-reference means to pass the reference of an argument in the calling function to the corresponding formal parameter of the called function. The called function can modify the value of the argument by using its reference passed in. The following example shows how arguments are passed by reference. So why cant we say java supports both. ?

[@sriharikaranam3330]

Java mainly dealing with 2 types.. 1. Primitive 2. Object In first case java is passing primitive value as argument of method. So any changes happened in method then new primitive will be created(which is short lived variable). It wont affect original primitive. In second case, lets say reference is 101011. Then java is passing that reference as argument of method. If any changes happened, reference value not get affected. Java will modify the object which is pointing to that reference. The reference value will be maintained as same. So Java is pass by value... In first case if original value changed, or in second case if the reference got changed, then it will be pass by reference..

[@abhishekganguly165]

@@sriharikaranam3330 what you told I got. but point is what is pass by reference then? we will pass the referance and address will be change? or pass by reference is we pass the referance and the value inside the referance got change?

[@sdef719]

Best explanation. Love it.

[@CodeDecode]

Thanks 👍

[@venkatesanelumalai-q5c]

Nice Video

[@CodeDecode]

Thanks

[@yoshitamahajan353]

In pass by value u mean the value doesn't change and in pass by reference value changed so ideally value changes when reference passed so it should be pass by reference?? Do let me know as I m still confused about this so

[@CodeDecode]

Ok so let's understand it in this way. Reference is nothing but memory address. Now when ever you change any thing at memory address, the change is reflected every where. Now in case of Java, This memory address is sent as values in arguments to methods. So it's pass by value, but since memory address or reference is passed as values hence changes are reflected every where

[@CodeDecode]

Now do you get the point?

[@yoshitamahajan353]

@@CodeDecode and same in case of pass by value we create copy of the variable and pass the copy.. so again we pass value.. 1. In call by value , we create copy of the value and pass to the method 2. In call by reference,we pass the value of memory address to which the object is passed So in both cases value is passed hence java is call by value Am I r8? Please correct me if I m wrong..

[@abhishekganguly165]

@@yoshitamahajan353 but both point 1 and 2 got satisfied right? so why this is only pass by value?? why it is not pass by refrerance?

[@gokulaher2476]

java is strictly pass-by-value method 'arguments' "value" initializes and assigns newly created method 'parameter'value

[@CodeDecode]

That's what we have discussed here also right?

[@gokulaher2476]

Perfect... Your video on java 8 Predicate,function, supplier,consumer Bi.... Predicate, fu,ction,consumer and stream are very well explained..

[@ayyappag7097]

Need small clarification, when primitive variable 'a' passed as an argument to a method you said java copies the value of 'a' to a new memory location and that location address passed to that method as argument so value wouldn't update in parent class ? Same theory isn't applicable to objects ? Java doesn't copy the object to different memory location and sends that memory location address to method as an argument ?

[@vaniraj8456]

No here because we send the reference variable which holds the memory address of an object rather than holding the object

[@AMANSINGH-yv4vv]

Thanks so much ya!

[@CodeDecode]

🙂👍

[@arpanbanejee5143]

Its still not clear to me- Example 1- If I just add tempList in my base case then I get [] [] [] [] as and, as it holds the reference and it gets modified in the recursive calls, so at each step when it hits the base case I need to capture the then state of the arraylist and store it in the res. private static void backtrack(List list, List tempList, int[] nums, int remain, int start) { if (start >= nums.length && remain != 0) { return; } else if (remain == 0) { list.add(new ArrayList(tempList));--> if I do not make a new list out of it , it gets modified. REFERENCE VAIRABLE THATS WHY!! } else { for (int i = start; i < nums.length; i++) { if (nums[i] > remain) { break; } if ((i > start && nums[i] == nums[i - 1])) { continue; // skip duplicates } tempList.add(nums[i]); backtrack(list, tempList, nums, remain - nums[i], i + 1); tempList.remove(tempList.size() - 1); } } } But in this example, even if I set the prev pointer when my left recurison ends for the first time ,still its value is null when it backtracks- private void convertBtToDll(Node temp, Node prev) { if (temp == null) { return; } convertBtToDll(temp.left, prev); // marks the head -- leftmost node if (prev == null) { head = temp; } // make the links for the other nodes else { temp.left = prev; prev.right = temp; } prev = temp; ----> even if I set it here it is null?????? why? isn't it a reference variable? convertBtToDll(temp.right, prev); } public static void main(String[] args) { ConvertBTtoDLL2 btToDll = new ConvertBTtoDLL2(); Node root = new Node(10); root = new Node(10); root.left = new Node(12); root.right = new Node(15); root.left.left = new Node(25); root.left.right = new Node(30); root.right.left = new Node(36); System.out.println("After conversion to DLL"); Node temp = root; Node prev = null; btToDll.convertBtToDll(temp, prev); btToDll.printDll(); }

[@hariprasad2697]

Super 🌟

[@CodeDecode]

Thanks hari

[@omprakash4558]

So can we say, java is pass by reference for non-premitive data types?

[@chaturvedisurbhi05]

So we can say reference is passed as value so reference doesn't change but object value gets change in case of passing reference?

[@deepkansara6547]

Consider this snippet: public static void main(String[] args) { Integer i = new Integer(3); modify(i); System.out.println(i); //Prints 3 } static void modify(Integer i) { i = i * 10; } In this case I have created the object of the Integer class and changed it's value. So as per this video, object can be changed as it is passed as a reference, I am getting the output as the same object it has been initialized with instead of modified version. In case of arrays, we can do modify the values of array. So I just want to know what kind of values are passed by value and what kind of values are passed by reference?? Anyone please help.

[@arpit2283]

Bro, String and Wrapper classes like Integer , Double , BigDecimal are immutable classes. So , the value is not changed there.

[@azizbekrasulmetov9293]

Did u said that u a passing object by value at the end ? When u actually passing the reference!

[@barathiraiyarul4498]

Thanks 👍

[@CodeDecode]

👍

[@aravindhravi2307]

THIS IS GR8!!!

[@CodeDecode]

Thanks 👍👍

[@gokudominic3328]

Why java is not both i.e. java is pass by value as well as pass by reference.??plzz ans

[@CodeDecode]

Because Java is pass by value. That's why it's not both.

[@gokudominic3328]

No mam i mean java is always pass by value but by vedio java is seems to be both so how can you say tha pass by reference is equivalent to pass by value??

[@gokudominic3328]

My actual question is how pass by reference is equivalent to pass by value??

[@CodeDecode]

Consider a scenerio : You are passing address or memory location itself.

[@CodeDecode]

So while you are passing your variable as formal argument of the method, it is considered as pass by value. So yes you are correct when you say it's pass by value but actually in java, you pass memory reference itself as a value.

[@poornachanderraonadipelly6128]

Mam im getting really confused with this concept? Please help me to understand

[@Rohit-yo4ik]

Today this question asked by interviwer...I got trapped... there is mutable/immutable thing also matter to this pass by value or reference. Please clear this also.

[@NareshKumar-dw9xp]

Yesterday I had an interview with Nokia , it was an on-campus placement interview.. You know what, they asked me why java is passed by value ? And they wouldn't satisfied with my answer. And hence I got rejected ☹️☹️.

[@CodeDecode]

Was I able to clear your query? Did you watch this video before or you watched this now?

[@NareshKumar-dw9xp]

@@CodeDecode That's the unfortunate mam. I watched it now. But noww I am clear amd confident. Probably next week I have an interview of TCS Digital SDE . I will never repeat this mistake ever. Thank you so much for this.

[@CodeDecode]

Don't worry. As a fresher you will get ample of opportunities and each interview will teach you something new.

[@CodeDecode]

Take it positively. Just make sure that you are clear with your basics. They will not go much high level. Prepare core Java thoroughly and I am sure you will crack something really worth cracking 👍

[@CodeDecode]

All the best for the future companies. 👍

[@asutoshsahoo3776]

Got it that , the reference we pass in java function is as a reference to memory location as value, so though we pass a reference it is still Pass by Value, but then what is Pass by Reference exactly

[@CodeDecode]

Your understanding is correct. Pass by reference is just a concept where you pass reference of variable or so called memory address of that variable itself as the formal argument. Doing so, if you change any thing locally in the method, the changes are no more local to that method, it's reflected every where Why so? Because you changed at the memory itself. Right? Now you got it ? If it would have been pass by value, different memory location is created for the formal argument and value will be copied. Hence if you change that value locally, the changes will be in newly created memory location and not in the original one

[@deneshbabu5199]

Then what exactly pass by reference?

[@abhishekganguly165]

@@deneshbabu5199 same question bhai.

[@abhishek_67]

Hum value bhi pass kr rhe hai aur object reference bhi pass kr pa rahe hai to java sirf passed by value kyu 🤔?

[@akshaydeshmukh1433]

call by rfrnce vs pass by rfrence same or dfrnt

[@swapnilhadge7383]

You missed to mention difference between int and animal ...

[@hasangalakdinu]

thanks!!!

[@CodeDecode]

You're welcome!

[@sharfan22010]

Thankyou miss👍

[@MultiMoonlight]

Ma'am is your name Sana?

[@temuryakhyoev5922]

still a bit confusing about pass the object as a parameter

[@paggybhangale]

how to write junit ? myovject oldermethod() { other call// hashmap map = new hashmap(): NewObj obj = service.myservice(map); //logic value = map.get(0); // here i am getting null pointer in junit test return myobject; } class myservice{ NewObj myservice(hashmap map) { //logic map.put(key,value): return Newobj; } } after that i am getting null if i mock the myservice ...how to write junit for oldermethod()

[@sahilbhasin2112]

gud job

[@CodeDecode]

Thanks :)

[@hhcdghjjgsdrt235]

you rock

[@CodeDecode]

:)

[@SaiAbitathaDUCIC]

My exam begins in 2 hours 🙏

[@CodeDecode]

All the best 👍💯

[@nazimmohammad6984]

Pl make it more clear.

[@siddharthb2226]

vera level

[@CodeDecode]

Thanks

[@hasnainansari6279]

I m still confused ⁉️

[@CodeDecode]

java is pass by value. But if you pass a reference variable as an argument and that changes then it is because you are passing memory reference as value. Hence it's never pass by reference. It's always pass by value.

[@CodeDecode]

Still confused??

[@littlethings2250]

@@CodeDecode : passing memory reference as a value? But here we are not working on copy, instead the actual object itself isn't it? And in C, the concept of pointers and reference, there we pass reference as a reference or value?

[@achyuth2424]

Not understood please give more detail easy way of understanding

[@CodeDecode]

Explaination : java is pass by value. But if you pass a reference variable as an argument and that changes then it is because you are passing memory reference as value. Hence it's never pass by reference. It's always pass by value. Still if it's not clear then please let me know I will put more examples for you.

[@achyuth2424]

@@CodeDecode more examples please

[@guntakasomeshwar8262]

I am unable to understand madam

[@shivprasadgonare4474]

plz provide notes

[@divyagracie]

02:51

[@unknownuser-wr3zm]

tq

[@CodeDecode]

👍

[@cousinslove7209]

Slow slow madam , not all members are quick learners as like you

[@CodeDecode]

Will try to reduce pace from next videos 👍

[@GameXanime63]

U can do by urself if u don't know the playback option just click on the three dot and u can this playback option where u can reduce the speed of the vdo btw thank me later

[@lazylizarts]

JAVA IS ALWAYS PASS BY VALUE ALWAYS

[@CodeDecode]

Can you please explain how?

[@lazylizarts]

@@CodeDecode its appropriate to say "Object reference is passed by value" for Non primitive type

[@horuscoming]

You got to activate windows.

[@CodeDecode]

Yeah will do that for sure...

[@sudipghimire4823]

This is too much of a hindi accent to take in..

[@CodeDecode]

We are so sorry Sudip that our mother tongue is hindi. 👍

[@hey_babe1557]

The video views is equal to your subscriber count

[@CodeDecode]

Nice observation Pradeep🙂👍

[@hey_babe1557]

@@CodeDecode 😁

[@venkatesanelumalai-q5c]

Good Video

[@CodeDecode]

Thanks