what access modifier is valid when not specified code example

Example 1: access modifiers in java

Example of private access modifier:

class Demo
{
   private void display()
   {
      System.out.println("Hello world java");
   }
}
public class PrivateAccessModifierExample
{
   public static void main(String[] args)
   {
      Demo obj = new Demo();
      System.out.println(obj.display());
   }
}

Example 2: What all access modifiers are allowed for top class

For top level class only two access modifiers are allowed. 
public and default. If a class is declared as public it is visible everywhere.
If a class is declared default it is visible only in same package.
If we try to give private and protected as access modifier to class 
we get the below compilation error.
Illegal Modifier for the class only public,abstract and final are permitted.