java eclipse main method and static class?

Firstly the correct object oriented way of calling a method (in this current block of code) is this.passMethod(x); But the variable x has been declared outside passMethod's scope, so that method doesn't know it exists. Try this: public class PassPrimitiveByValue { int x = 3; public static void main(String [ ] args) { this.passMethod(x); System.out.println("The value of x is: " + x); } public static void passMethod(int p) { //Printing parameter p value. System.out.println("value before change:"+p); p = 10; System.out.print(p); System.out.print(x); } }

Well, like the error message says, a top-level class can't be static, private or protected. Since you mention "static class" in your question, I'm assuming you have the word static in your class definition. Remove it. Static outer classes do not exist in Java.

As for the first one, it's probably because your main() method doesn't have the right signature. To work properly, a main method in a Java class needs to be declared like this:

public static void main(String[] args) {

// do stuff

}

If you want more specific help, you'll need to actually show us the code you're working on.