Returning a value across classes

[anon538]

I have a class named collect.java that looks like this:

public class collect {
    public int returnX() {
        int x=5;
        return x;
    }
}
 

I also have a main class-

public class testcollect {
    public static void main(String[] args) {
        collect collector = new collect();
        collector.returnX();
        System.out.println(x);
    }
}
 

I was expecting the testcollect class to simply print out 5. Yet I get the error message "cannot find variable x". Please help.

[Ganon11]

Read exactly what the message says. There is no variable x in your main() program. The variable x is not returned by your function - only its value. In order to catch that value, you need to store it in your own variable. If you change your main to:

//...
int x = collector.returnX();
System.out.println(x);
//...

it will work as expected.

[anon538]

Thank you! I feel so stupid for not thinking of that.

[Ganon11]

You're welcome. Functions returning values is a fundamental concept in programming, so make sure you understand it well (and understand functions that don't return values as well).