What concept in Java makes it "write once, run anywhere"? The concept in Java that makes it "write once, run anywhere" is the Java Virtual Machine (JVM). Java programs are compiled into bytecode, which is platform-independent. The JVM interprets this bytecode and runs it on any device or operating system that has a compatible JVM implementation. Can we run a Java program without a main method? No, we can't run java program without a main method because the main method is the entry point of java program if main method is not present in the program then it will throw compilation error indication no main method is found Difference between JRE and JDK - **JRE (Java Runtime Environment):** It is a package of tools necessary to run Java programs. It includes the JVM, core libraries, and other components required to run applications written in Java.
- **JDK (Java Development Kit):** It is a superset of the JRE, containing everything in the JRE plus tools for developing Java applications, such as the compiler (`javac`), debuggers, and other development tools. What is a wrapper class? A wrapper class in Java provides a way to use primitive data types (int, char, etc.) as objects. Each primitive data type has a corresponding wrapper class: - int -> Integer - char -> Character - boolean -> Boolean - etc. Wrapper classes are used for converting primitives to objects and vice versa, which is especially useful in situations where objects are required, such as in collections. What will happen if we do not write `static` with the main method? If the `main` method is not declared `static`, the JVM will not be able to call it at the start of the program. This is because the `main` method is the entry point of the program and is called without creating an instance of the class. Declaring `main` as `static` allows the JVM to call it directly using the class name. Can we have multiple main methods in Java? Yes, you can write multiple main methods in Java. But, only one main method with a parameter as String[] args will be executed by the JVM. The main method is the entry point of a Java program. It is the method that is called when the program is executed. The main method must be declared public static void main(String[] args). If you have multiple main methods in your program, only the one with the correct signature will be executed. The other main methods will be ignored What is method overloading? Method overloading in Java is a feature that allows a class to have more than one method with the same name, but different parameter lists (different type, number, or both). The appropriate method is selected based on the method signature at compile-time. Can we have multiple catch blocks with a single try block? Yes, you can have multiple catch blocks with a single try block in Java. Each catch block can handle a different type of exception. The first catch block with a matching exception type is executed. ```java try { // code that may throw an exception } catch (IOException e) { // handle IOException } catch (SQLException e) { // handle SQLException } catch (Exception e) { // handle any other exceptions } ``` Difference between array and ArrayList - **Array:** - Fixed size: Once created, the size cannot be changed. - Can hold primitive types and objects. - Not part of the Java Collections Framework. - **ArrayList:** - Dynamic size: Can grow and shrink as needed. - Can only hold objects (wrapper classes for primitives). - Part of the Java Collections Framework and provides more functionality, like dynamic resizing and methods for manipulation. Why is Map not considered a Collection? In Java, the `Map` interface is not a part of the `Collection` hierarchy. While `Collection` is a root interface for collections like `List`, `Set`, and `Queue`, `Map` is designed to store key-value pairs and thus does not fit into the `Collection` interface's structure, which is more suited for single elements. The `Map` interface has a different structure and methods tailored for key-value associations rather than individual elements.
Nowadays they expect spring, spring boot,hibernate and microservices knowledge from a fresher. They are not even shortlisting resumes of those who only knows core java.
1.Jdk is a software where as jvm is virtual mechine which is compile the code, inside jdk software there is jvm 2. Yes we can use more than 1 main method but jvm only execute that main method which has String arg[]
@@nationfirst640 Right. That's what I said too. The original comment says ".....JVM is virtual mechine which is compile the code..." and I corrected it, because that's wrong.
@@nationfirst640 I don't want to disappoint you. "Yes. I am the best developer in this entire universe. You are all subordinates to me. You should listen whatever I said to you."
Subclass exception type should be defined first that means in first catch block we have to define Arithmetic exception and in the next catch block we have to define superclass exception type that we can say like try{ Exception causing statements } catch(ArithmeticExc.. e) { Sopl("handled"); } catch(Exception e) { Sopl("Exception handled"); } Once the exception handled control doesn't go back to try block to check remaining statements. Statements after exception handling mechanisms will then get executed.
If we have to store homogeneous objects or fixed size we can prefer array and opposite of that if we want to store heterogenous object with dynamic content we can use arraylist.
Array doesn't based on Some standard data structures,so predefine method support not present in case of arrays like Arraylist have .....Array is type safe and faster then Arraylist...
We can hire you .....but along with java you atleast must have 30 years of programming experience in dart, php, python, javascript, typescript with no expectations......you must have a really high knowledge in AWS, firebase Along with it you must have advance knowledge about mysql, all the nosql's available in the market, cloud databases, and relational databases You must have a deep knowledge and atleast around 400 projects with frameworks like react, flutter, django, flask, express You must know how to handle a large Team with a members of only you(as we are short on staff), when we provide you 30 projects together If you think you are capable on working under these conditions....we are happy to hire you with a monthly salary of 5000 Feel free to contact us
In stand alone applications main method is required, but in web or enterprise application which is not required because the whole execution will depend on web server we use
One interview I did, by the end I had literally created an app for the company. I didn't get the job but I found out that they took the app and made millions of dollars from it. 😄
If any relation between exception then child class exception should write in upper and parent class should write lower otherwise it will give COMPILE ERROR...
10:00 case1 - --------- If the Superclass is mentioned in the 1st catch block and ArithmeticException is defined in the 2nd catch block Result - CE : exception ArithmeticException has already been caught catch(ArithmeticException ae) ============================================== case2 - ----------- If the Superclass is mentioned in the 2nd catch block and ArithmeticException is defined in the 1st catch block Result: No CE Error Just the statements mentioned in the ArithmeticException of the 1st catch block will be matched and executed
yes you are but they don't onboarding freshers cause of recession it may take upto 4 months to onboard freshers if you are selected to wipro elite. all the best
His eye contact is not that great...i used to be like him...but later i improved my eye contact...but his communication skills and knowledge is good 👌🏻
Jsp and servlet is no more used in the industry almost dead, its time of AI,jdk.11,spring boot, kafka,Angular and microservices etc. lockdown questions are very basic and even ppl got seleted
we must pass a try and catch exception in our code. For example, a = 10; b = 5; c = 5; result = a/(b-c); The result is not possible since nothing can be divided by zero. So we need to write a catch statement calling the ArithmeticException so it can just skip the result when the denominator gets 0.
correct...it's just for educational purposes....i have seen a similar SQL interview where Vishal was the interviewer and the candidate was someone else
![เจ้าผู้เดียว - ดิด คิตตี้ [OFFICIAL MV]](http://i.ytimg.com/vi/q0NLCYKBOTo/mqdefault.jpg)
Interviewer Roshni has a smiling face. This makes the candidate feel comfortable and answer the questions.
Bhai dil ki bat bol diye ap
+1
both are trainer that why 😂
@@annujamre286 more of for for of of of a a good and I is
Yes 👍
What concept in Java makes it "write once, run anywhere"?
The concept in Java that makes it "write once, run anywhere" is the Java Virtual Machine (JVM). Java programs are compiled into bytecode, which is platform-independent. The JVM interprets this bytecode and runs it on any device or operating system that has a compatible JVM implementation.
Can we run a Java program without a main method?
No, we can't run java program without a main method because the main method is the entry point of java program if main method is not present in the program then it will throw compilation error indication no main method is found
Difference between JRE and JDK
- **JRE (Java Runtime Environment):** It is a package of tools necessary to run Java programs. It includes the JVM, core libraries, and other components required to run applications written in Java.
- **JDK (Java Development Kit):** It is a superset of the JRE, containing everything in the JRE plus tools for developing Java applications, such as the compiler (`javac`), debuggers, and other development tools.
What is a wrapper class?
A wrapper class in Java provides a way to use primitive data types (int, char, etc.) as objects. Each primitive data type has a corresponding wrapper class:
- int -> Integer
- char -> Character
- boolean -> Boolean
- etc.
Wrapper classes are used for converting primitives to objects and vice versa, which is especially useful in situations where objects are required, such as in collections.
What will happen if we do not write `static` with the main method?
If the `main` method is not declared `static`, the JVM will not be able to call it at the start of the program. This is because the `main` method is the entry point of the program and is called without creating an instance of the class. Declaring `main` as `static` allows the JVM to call it directly using the class name.
Can we have multiple main methods in Java?
Yes, you can write multiple main methods in Java. But, only one main method with a parameter as String[] args will be executed by the JVM.
The main method is the entry point of a Java program. It is the method that is called when the program is executed. The main method must be declared public static void main(String[] args).
If you have multiple main methods in your program, only the one with the correct signature will be executed. The other main methods will be ignored
What is method overloading?
Method overloading in Java is a feature that allows a class to have more than one method with the same name, but different parameter lists (different type, number, or both). The appropriate method is selected based on the method signature at compile-time.
Can we have multiple catch blocks with a single try block?
Yes, you can have multiple catch blocks with a single try block in Java. Each catch block can handle a different type of exception. The first catch block with a matching exception type is executed.
```java
try {
// code that may throw an exception
} catch (IOException e) {
// handle IOException
} catch (SQLException e) {
// handle SQLException
} catch (Exception e) {
// handle any other exceptions
}
```
Difference between array and ArrayList
- **Array:**
- Fixed size: Once created, the size cannot be changed.
- Can hold primitive types and objects.
- Not part of the Java Collections Framework.
- **ArrayList:**
- Dynamic size: Can grow and shrink as needed.
- Can only hold objects (wrapper classes for primitives).
- Part of the Java Collections Framework and provides more functionality, like dynamic resizing and methods for manipulation.
Why is Map not considered a Collection?
In Java, the `Map` interface is not a part of the `Collection` hierarchy. While `Collection` is a root interface for collections like `List`, `Set`, and `Queue`, `Map` is designed to store key-value pairs and thus does not fit into the `Collection` interface's structure, which is more suited for single elements. The `Map` interface has a different structure and methods tailored for key-value associations rather than individual elements.
Nowadays they expect spring, spring boot,hibernate and microservices knowledge from a fresher. They are not even shortlisting resumes of those who only knows core java.
1.Jdk is a software where as jvm is virtual mechine which is compile the code, inside jdk software there is jvm
2. Yes we can use more than 1 main method but jvm only execute that main method which has String arg[]
JVM won't compile any code. It executes compiled code.
@@Kumbutranjaamiit's compiler like Javac present in jdk that compile the code
@@nationfirst640 Right. That's what I said too. The original comment says ".....JVM is virtual mechine which is compile the code..." and I corrected it, because that's wrong.
@@Kumbutranjaami you're right bro,you said it right, I just said mentioned about javac , that's it.
@@nationfirst640 I don't want to disappoint you. "Yes. I am the best developer in this entire universe. You are all subordinates to me. You should listen whatever I said to you."
The Roshni is very simpatic, She make this interview more easy.
Subclass exception type should be defined first that means in first catch block we have to define Arithmetic exception and in the next catch block we have to define superclass exception type that we can say like
try{
Exception causing statements
}
catch(ArithmeticExc.. e)
{
Sopl("handled");
}
catch(Exception e)
{
Sopl("Exception handled");
}
Once the exception handled control doesn't go back to try block to check remaining statements. Statements after exception handling mechanisms will then get executed.
Agreed
in that case Exception block will handle the exception first
@@humtum4484 yes this will show a error at compile time that ArithmeticException has been caught.😊
If we have to store homogeneous objects or fixed size we can prefer array and opposite of that if we want to store heterogenous object with dynamic content we can use arraylist.
you can also store heterogenous in an array and do same things like in a collection, taking about objects
These kinds of mock interviews will help to students.
Array doesn't based on Some standard data structures,so predefine method support not present in case of arrays like Arraylist have .....Array is type safe and faster then Arraylist...
Channel name itself 😍 xplains a lot
They can take common of the repeating name... 😀😀😀😀
4 questions.= answer is besically try and catch block exception handling
static in method means you don't have to create object to call main method. main method automatically will call, when you run the program.
I felt that am only taking interview ✨
Nice interview... And it's more practical...
Roshni😍maam smiling face building confidence for opposite person
Roshni smile makes also feel free
Thanks for your help 🙂👍👍👍👍👍
Wrapper class converts primitive datatype into OOP
JVM only run one main method which contains argument as string array
i know each and every answer she asked with perfect example
you are getting the job let me hire you
@@randomanimememes2685 for which post ?
@@surajprajapati7027 for proxies…..😂😂😂
We can hire you .....but along with java you atleast must have 30 years of programming experience in dart, php, python, javascript, typescript with no expectations......you must have a really high knowledge in AWS, firebase
Along with it you must have advance knowledge about mysql, all the nosql's available in the market, cloud databases, and relational databases
You must have a deep knowledge and atleast around 400 projects with frameworks like react, flutter, django, flask, express
You must know how to handle a large Team with a members of only you(as we are short on staff), when we provide you 30 projects together
If you think you are capable on working under these conditions....we are happy to hire you with a monthly salary of 5000
Feel free to contact us
Number please
The interviewer always smile like she put a difficult question and let's see how he gonna answer it
Tq u this is helpfull for all
After listening this...i can feel like clear this round . 😂😂.. easy questions
Yes bro, I also feel like that
I feel like its scripted means he dosnt look fresher 😅
@@Artified00 😂
@@Artified00 it's not like that, he was confident, if he didn't knew the answer also he seemed confident
@@Artified00 it is a mock interview. He is a senior at tcs already
We can run java code without using main method by using static block which runs only once when class is loaded in to the meory
not now in earlier version we can run without main
But it was possible the previous version
In stand alone applications main method is required, but in web or enterprise application which is not required because the whole execution will depend on web server we use
After asking every question.. madam smiling 😀❤️
Smiling
Most of the interviews are nowhere as easy as this one is, don't be fooled.
Yes... How come it is so easy 😂
most of the answers are like this dumb..
Actually she has made her mind to reject him. Thats why she thought why to waste more time 😅
One interview I did, by the end I had literally created an app for the company. I didn't get the job but I found out that they took the app and made millions of dollars from it. 😄
@@Neerajkushwaha-uz8wobut how did you came with conclusion that she wanted to reject him
Thank you for making such kind of video,this is not real but it's good
I think this ia real i searched her on LinkedIn and she really work in tata elxsi as a senior manager.
If any relation between exception then child class exception should write in upper and parent class should write lower otherwise it will give COMPILE ERROR...
actually its arraylist not error list as captions heard it wrong
Main m static isliye chahiye kyunki we can't create object of that and we need static keyword so that we can invoke main method.
I am just focusing on java interview questions for selenium interview to crack
10:00
case1 -
---------
If the Superclass is mentioned in the 1st catch block and ArithmeticException is defined in the 2nd catch block
Result - CE :
exception ArithmeticException has already been caught
catch(ArithmeticException ae)
==============================================
case2 -
-----------
If the Superclass is mentioned in the 2nd catch block and ArithmeticException is defined in the 1st catch block
Result: No CE Error
Just the statements mentioned in the ArithmeticException of the 1st catch block will be matched and executed
This concept comes in advance java? Please tell me.
@@basuchouri324 not sure , but I learned as part of J2SE (core Java)
kash har interviewer mam jaise ho
If you share his resume here , it will be helpful.
What if we use static block over main method it will execute it
We can run Java program without main method before Java 7.
Very nice interview with smily faces😂
This interview was an expectation but reality is different😂
Yup bro 🤣
Is the real one is tough than this?....
Haha 😂 obviously!! This is the way these TH-camrs make money
@@parameshiyer6065 this is tcs not a product based company who asks u regarding DSA so yeah it is the almost same interview expected by tcs
could you elaborate and tell me which type of question we can expect as a fresher in an interview?
I selected in wipro on phase 2... And i had completed my graduation this year 2022.. And i have 6.29cgpa...now am i eligible for wipro🥺🥺🥺
yes you are but they don't onboarding freshers cause of recession it may take upto 4 months to onboard freshers if you are selected to wipro elite. all the best
Hey ....how u did it can u help me..
don't join wipro
cse or btech or bca ?
@@tsunium2662 why.?
Nice discussion
Can we overload main method?
Yes We can overload main method by changing its formal arguments.
yes we can overload main method but jvm calls main method with (string args[]) only
Yes
Interviewer roshni mam face was very likely and very interested to say answers by seeing mam
👍👍
looks like he is not a fresher ....!!!his age is far than fresher ..i think soo...
40 ka lagta hei
Problem with me is that .. if you give me a question i could solve it easily .. but can't explain it in English ...
Me too 🙂
His eye contact is not that great...i used to be like him...but later i improved my eye contact...but his communication skills and knowledge is good 👌🏻
He looks experienced guy but questions are very basic level.
wrapper class wraps around data data type and give it an form of object, the preemptive data type cant be wrap because they do not belong to any class
It seems that I have gone through your resume 😂 Typical Indian Software Engineer English 😂
Exception da
Could we get videos of tcs digital interviews???
His answer is perfect
One or two methods same object,but different values
is it for ninja role or digital role??
Is this ninja or digital ?
I can give answer for all this question but still I could not able to crack any interview for java development. Very sad
Why bro what happened
Being a mechanical engineer I can answer all this questions
It easy say bro
Jvm Jdk java vartual machine/ java development kit ♥️
Why is he unable to give a simple answer?
It was a basic level answer
Jsp and servlet is no more used in the industry almost dead, its time of AI,jdk.11,spring boot, kafka,Angular and microservices etc. lockdown questions are very basic and even ppl got seleted
can somebody comment the y=10/0 question as how it would have been presented/written if it was a code.
we must pass a try and catch exception in our code.
For example,
a = 10;
b = 5;
c = 5;
result = a/(b-c);
The result is not possible since nothing can be divided by zero. So we need to write a catch statement calling the ArithmeticException so it can just skip the result when the denominator gets 0.
@@purplewolf3769 it should be a/(b-c)
@@rexkrish3852 oops.. TYPO
Runtime error is the keyword
@@purplewolf3769then fix it blud. 😅
No need of any more interview anyways we have chatgpt now
is this ninja or digital interview?
Can I give the interview
Wrapper class
Itna aasan interview kon leta h bhai....Sab jhut hai..Sab moh maya hai
is that off campus interview?
Doesn't matter, follow up with the questions it will help
@@SumanRoy.official asking bcoz we dont have campus placements , also companies like TCS dont come in our collage.
Ya it’s an off campus
Script broi
@@sandeeprn6959 yeh its sounds like ..
If statement
Void
In tino me se freser kon lagra
They all of are.
all are recruiters
😃
lol
That mam
Scripted
I dont think so
Vishal Barad is the head of TCS Xplore 😂 that's enough to tell you
correct...it's just for educational purposes....i have seen a similar SQL interview where Vishal was the interviewer and the candidate was someone else
Is that joke
looks like
🤣🤣
😂😂
Is he fresher?
Yes... But at looking him anybody can say he completed his graduations 10 years before...
@@pawantembhurne6828 this is not a real interview it's just a demo of how it is
System.out.print("Thank you");