A static method can NOT access a Non-static method or variable.
public static void main(String[] args) is a static method, so can NOT access the Non-static public static int fxn(int y) method.
Try it this way...
static int fxn(int y)
public class Two {
public static void main(String[] args) {
int x = 0;
System.out.println("x = " + x);
x = fxn(x);
System.out.println("x = " + x);
}
static int fxn(int y) {
y = 5;
return y;
}
}