static variable -- confusion?

[Badri Sarma]

Hi,

Below is the prgram

class Test{
static int j = 100;
static{
j = 200; // line 1
i = 500; // line 2
i = i + 1; // line 3
System.out.println(j+":value:"+i); // line 4
}
static int i = 200;
}

My assumption is error to be raised at line 2.
But error is raised at line 3.


Please let me know wky..

[vinod balaji]

Dear Badri
Your code will produce forward reference error.

class Test{
static int j = 100;

static{
j = 200; // line 1
i = 500; // line 2
i = i + 1; // line 3
System.out.println(j+":value:"+i); // line 4
}
static int i = 200;
}

There wont be error in line 2, because since i is in static block(it means that declaration part is there somewhere). Error is shown in line 3 as i value is being used before the declaration line.

If you change the code as
class Test{
static int j = 100;
static int i = 200;
static{
j = 200; // line 1
i = 500; // line 2
i = i + 1; // line 3
System.out.println(j+":value:"+i); // line 4
}

}

It works fine.

If any thing is wrong, please let me know

Bye

[Badri Sarma]

Thanks Vinod for the reply. But still i have a doubt....

Originally posted by vinod balaji:

There wont be error in line 2, because since i is in static block(it means that declaration part is there somewhere).

Why the i = i + 1, cannot think in the same fashion as you mentioned "it means that declaration part is there somewhere" and compile the code.

[vinod balaji]

this is the forward reference method.

Eg:
a=1; // here a will be assigned to 1
a=a+1; // here a will be incremented and then assign


In that program(Your Program), assigning gives no problem, it will not allocate memory until it finds the declaration, but while u use a=a+1, it will see the right hand side value(a+1) where it will think that value hasnt been declared and it will issue forward reference error

i think it is clear, if u still have doubt reply me.

[Badri Sarma]

Vinod Thanks for replying to my queries.
But still doubt persist in my mind it is not 100% clear.
Can you brief me on "forward reference error".

[wise owen]

Forward Referencing