How can I call a variable from another class

If the variable is public, you can just access it directly, as in the following example:

class MyClass2

{

public int action;

}

class MyClass1

{

public void someMethod()

{

MyClass2 myClass2 = new MyClass2();

myClass2.action = 7;

// ...

int theAction = myClass2.action;

}

}

However, it's bad form to have publicly accessible variables. You should use getter and setter methods to allow access to class properties, like this:

class MyClass2

{

private int action; // now nobody can access it directly

public int getAction() // callers have to go through this getter method

{

return action;

}

public int setAction(int newAction) // callers have to go through this setter method

{

action = newAction;

}

}

class MyClass1

{

public void someMethod()

{

MyClass2 myClass2 = new MyClass2();

myClass2.setAction(7);

// ...

int theAction = myClass2.getAction();

}

}

Using getters and setters allows you to provide "read only" variables (i.e. a getter but no setter) if you want to, and also allows you to hide the implementation of a variable (i.e. maybe every time getAction() is called we look up a value in a database or out of a file or something - the point is the caller doesn't have to know or care). Also, it allows us to enforce certain checks on new values in the setter method to ensure that the new value makes sense (for example, setAction() could reject any number less than zero, thereby ensuring that the value of action is always positive, if need be).

scorbett at 2007-7-7 1:10:05 >

This line:

MyClass2 myclass2 = new MyClass2();

doesn't really "execute" MyClass2, although it does cause the contents of MyClass2's default constructor to be run. Is that what you mean? If you mean that MyClass2 has a main() method that can be used to execute MyClass2 as an application, then no, the above line of code won't cause that to happen.

scorbett at 2007-7-7 1:10:05 >