Static

[Nishant Modak]

 
public class staticFun {

static int a;
public staticFun getM(){
return new staticFun();
}
static  public void main(String ... args) {
System.out.println(new staticFun().getM().a); // Line 1
//System.out.println(a);
}
 
}

Output of Line 1 is 0. :roll:
I thought it would be NullPointerException..

Help ..

[Costa lamona]

static keyword means that decleration is part of the class not the object, so you can invoke getM() by calling staticFun.getM() or by simply calling getM() because you are inside the class.

you can access getM() by ref pointing to staticFun, like this
new staticFun().getM(), but this cause irreadable code, you shouldn't do this.

and because all attributes initialized with 0 in java when class is loaded in case of static attribute, or when object is instantiated for instace variables. so the output is 0

hint:
static have nothing to do with instace, it works on the ref type. so there is no chance to have nullPointerException.
you may be just miss to read "static"

you will find 1000 tutorial on the web for static context.

[Burkhard Hassel]

Hi ranchers,

Two remarks, first:
static members (both variables and methods) can be accessed through an instance of the class,
even if the instance is null:

class EasierStaticFun {
static String hi = "Hi Nishant!";
static String method(){
return hi;
}
public static void main(String [] args){
EasierStaticFun fun = null;
System.out.println(fun.hi);
System.out.println(fun.method());
}
}

prints twice "Hi Nishant!", no exceptions.


However it is bad coding style to do so. Static members should be accessed through the class name.



Second:

in the original code from Nishant, there would be also no null pointer exception, if the variable a was not static. The method returns a new instance of staticFun. And this instance is not null, even though it is not referenced by any variable.



Yours,
Bu.