The following code showing error . . . . I just want to know the reason .

[rajpan06]

class This1{
void show(){
System.out.println("abc");
}
}
public class ThisTest { This1 t1=new This1();
public static void main(String[] args) {
t1.show();
} showing compile time error
}


[JosAH]

Make your This1 t1 static.

kind regards,

Jos

[rajpan06]

After adding static keyword to This1 t1=new This1(); program executed correctly but till now i don't understand why we are using static keyword there . Is it compulsory to make static any thing out side the main method. Thanks for response.

[Junky]

You have to fully understand what static means. I suggest you read your notes, textbook or search online.

Static means that it belongs to the class and not to an instance (object) of that class. In your code you have declared the t1 variable to be an instance variable of the ThisTest class which means you need to create an instance of that class to access the t1 variable.

Another way to look at it is to remember that the main method can be moved out of your ThisTest class into any other class.

class Junky {
    public static void main(String[] args) {
        t1.show();
    }
}

You get the exact same problem since my class has zero information about the t1 variable.

[rajpan06]

class This1{
void show(){
System.out.println("abc");
}
}
public class ThisTest {
static This1 t1=new This1();
public static void main(String[] args) {
t1.show();
}
}
the above code not showing any error . But if i write like this. . class This1{
void show(){
System.out.println("abc");
}
}
public class ThisTest {
This1 t1=new This1();
public static void main(String[] args) {
t1.show();
}
}
 it is showing error . . 

[JosAH]

See my first reply (reply #2).

kind regards,

Jos

[Junky]

 it is showing error . . 

Exactly as it has already been explained.

[JosAH]

I'm afraid the OP doesn't understand what the keyword 'static' means; as many others do, they sprinkle in the keyword 'static' here and there until the compiler keeps its mouth shut. The answer is in the tutorials (as always).

kind regards,

Jos

[Junky]

Which is why I suggested they read about static and even provided an explanation. It obviously went whooooosh!

[JosAH]

Which is why I suggested they read about static and even provided an explanation. It obviously went whooooosh!

You must've accidentally pressed the 'invisible ink' button before you submitted your reply; it happens to me all the time ...

kind regards,

Jos