Cannot "see" a method from a different class?

[Gary Hill]

Hi,

I am new so may have some terminology wrong!

I am trying to access a method from my main class, i have created an object and i can access this method from Main.

But if i then try and access it from another method it cannot be seen and i cannot compile my code.

In public void test() the compiler says "variable Window cannot be found". Obviously this is not supposed to be a variable!
It also has a thin red squigly line under Window (as its an error in Netbeans)

I have stripped the code down to the minimum for clarity on here.

I would appreciatte some help. Thanks

Regards


Gary



Please see code below:

package javaapplication14;

public class TwoWaySerialComm {

    public TwoWaySerialComm() {
        super();
    }

    public static void main(String[] args) {

        WindowSetUp Window = new WindowSetUp();     // New object
        Window.doNothing();                         // THIS SHOWS AS CORRECT !

    }

    public void test() {

        Window.doNothing();                         // compiler says "variable Window cannot be found" ?

    }
}

package javaapplication14;


public class WindowSetUp {
    
       
     public void doNothing () {

    }

}

[Tom Reilly]

Your Window variable is local to the main() method. Methods can not see local variables declared in other methods. If you want to see a variable from multiple methods, you must declare it at the class level.

[J. Insi]

yes, he was right.

you need to change the variable declaration to be class level
instead of local level (those located at your main method only).

Here more revised from your code.
Put the variable out of your main method.

package javaapplication14;

public class TwoWaySerialComm {

   static WindowSetUp Window = new WindowSetUp();     // New object

.... 

    public void test() {

        Window.doNothing();                         // compiler says "okay"

    }


}

[Gary Hill]

Thanks J Insi and Tom

That has solved my problem!

Its obvious now

Regards


Gary