Why StackOverflow Error ? [Solved]

Question

This is simple java program. In this program i just created two objects and nothing else.
Anyone know why this error is comming.

https://code.sololearn.com/c14nDb01b6M2/?ref=app

Answer 1

P∆WAN M∆URY∆

https://code.sololearn.com/cVNml5BVo1SY/?ref=app

Answer 2

P Jain you meant final keyword creating issue

as per your last statement

Answer 3

P Jain 😂 ok update

Answer 4

You are making a new object of a class that's constructor also makes a new object of itself and that further makes new object and so on!
Again again and again!
So we are making unlimited number of objects of this class!
You can add a static variable that is increased when an object is made (i.e. constructor) and put an if statement (or a base case) to prevent this Error!

Answer 5

Namit Jain What do you want to explain in this code.

Answer 6

Namit Jain we can put in block.
If you heard about static and instance block.😅

And I'm not going to perform explicitly recursion

Answer 7

P∆WAN M∆URY∆ Before calling constructor it call x1=new Program() ;
This it self calls same class infinitely...

Answer 8

Namit Jain which line creating issue?

Answer 9

Namit Jain if I will comment line 10 will it give me error ?

Answer 10

P∆WAN M∆URY∆ no

Answer 11

Namit Jain In this program you are explicitly creating a recursion and break it.

In my question I didn't use this.

Answer 12

P∆WAN M∆URY∆
You cannot put an if statement outside a method 😏🤔
So, how will you stop it without if statement 😑

Answer 13

P∆WAN M∆URY∆ yaa! Block is necessary 🙃
But i don't think we can declare variables here

Answer 14

The most simple explanation here(For those who not understand stack and heap) :
Basically you're initialising an object of the same class as a member variable. This causes the JVM to find the constructor of the Program which has not been invoked upon yet(because the JVM always inits the members first) so the constructor which is been called makes another call to the constructor and which again makes the same thing... Goes on... Results into Stack Overflow.

Basically you can't create a final object of the same class as a member variable(because you'll have to initialize it either in class block or constructor block which'll cause Stack Overflow). you also can't initialize a normal member(in class or constructor block).

Answer 15

P∆WAN M∆URY∆ no I meant that object as a member variable initialisation is the cause of the error.
Oops looked up now ... 😂😂😂 By mistake final was typed... Wait I'll correct that.

Answer 16

P∆WAN M∆URY∆ corrected 👍

Answer 17

public class Program
{
// final Program x1 = new Program();

Program() {
System.out.println("stack over?");
}
public static void main(String[] args) {

Program x1 = new Program();

}
}

P∆WAN M∆URY∆ Before calling constructor it call x1=new Program() ;
This it self calls same class infinitely.....

Answer 18

P∆WAN M∆URY∆ that there should be a limit!
Like here there is a limit of 50
The class should not make its instance if it exceeds the provided limit (50)

Answer 19

P∆WAN M∆URY∆ line 3

Answer 20

P∆WAN M∆URY∆
This will help you!

https://code.sololearn.com/cIh2UHxyrrzt/?ref=app