What would happen if an object is created in non-static method of class in java?

Question

class Data {
    int x = 20; // instance variable

    public void show() // non-static method
    {
        Data d1 = new Data(); // object of same class Data
        int x = 10;
        System.out.println(x); // local x
        System.out.println(d1.x);// instance variable x
    }

    public static void main(String... args) {
        Data d = new Data();
        d.show(); // "10 20"
    }
}

So my question when an object is created in show() namely 'd1' , it must have its own set of data members and must have allocated a new stack for its show() method , which in return should create a new object and thus the cycle should go on and stack-overflow occurs?? But this is working perfectly fine??

_must have allocated a new stack for its show()_ But you didn't invoke its `show` method. Why would it get executed? — Sotirios Delimanolis, Jan 07 '16 at 16:14
Try calling `show()` in the constructor of your class and see **magic** happen — TheLostMind, Jan 07 '16 at 16:16
so, isn't it like memory is automatically allocated for methods()? — Gagan, Jan 07 '16 at 16:16
Even if memory is allocated, isn't that different than **invoking** a method? Do you think when you create an object all methods would be invoked by default while creation? — Atri, Jan 07 '16 at 16:17

score 2 · Accepted Answer · answered Jan 07 '16 at 16:21

2

Data d1=new Data();

this statement itself will not allocate a new stack for show(). show()'s stack is allocated only when it gets called, for example, when it gets called in main.

answered Jan 07 '16 at 16:21

liusy182

205
1
7

Thank you very much for your effort – Gagan Jan 07 '16 at 16:21

score 1 · Answer 2 · answered Jan 07 '16 at 16:19

Your show() method will be called only once. show() is NOT called when an instance of Data is being created. So, you will not get SOE.

Try this code to get SOE :P

class Data {
    int x = 20; // instance variable

    Data() {
        show(); // This will cause SOE
    }
    public void show() // non-static method
    {
        Data d1 = new Data(); // object of same class Data
        int x = 10;
        System.out.println(x); // local x
        System.out.println(d1.x);// instance variable x
    }

    public static void main(String... args) {
        Data d = new Data();
        d.show(); // "10 20"
    }
}

just kidding buddy , but this really helped – Gagan Jan 07 '16 at 16:30 — Gagan, Jan 07 '16 at 16:30

What would happen if an object is created in non-static method of class in java?

2 Answers2