"Creating" an object in java

Question

Like I have such code:

class myobj {
    public static int i;

    public myobj(int _i) {
        i = _i;
    }
}

public class mainclass {
    public static void main(String[] args) {
        myobj a = new myobj(1);
        myobj b = new myobj(2);

        System.out.println(b.i); // Prints 2 - expected
        System.out.println(a.i); // Prints 2 - unexpected
    }
}

And I want a.i to be 1.

How can I make a 'new' object?

Answer 1

Remove the static declaration. Declaring something as static means that it will be shared across all instances of a class. So in your code, both a and b were using the same i variable. If we just remove the static modifier, your code works as expected.

class myobj {

    public int i;

    public myobj(int _i) {
        i = _i;
    }
}

public class mainclass {

    public static void main(String[] args) {
        myobj a = new myobj(1);
        myobj b = new myobj(2);

        System.out.println(b.i); // Prints 2 - expected
        System.out.println(a.i); // Prints 2 - unexpected
    }
}

Answer 2

Make this:

public static int i;

this:

public int i;

Everything else is fine.

Answer 3

Given what you've asked change this

public static int i;

to

public int i;

Because a static field is shared by all instances of myobj.

Answer 4

if you write your class that way

public static int i;

only one i will be created and this i will be shared with all object of myobj ever created.That what static key word means and used for. Read this thread for better understanding. I if want i once a myobj created remove the static keyword

public int i;