changes if using import instead of same package

Question

Today I wrote an exam and there was this question, which lines of code won't work if we write import countries.*; instead of package countries; in the TestCountry class. Here's the two classes:

package countries;

public class Country {
    private String name;
    private int population;
    boolean isEuropean;
    public double area;
    protected Country[] neighbors;

    protected boolean inEurope() {
        return this.isEuropean;
    }

    private void updatePopulation(int newBorns) {
        this.population += newBorns;
    }

    public String toString() {
        String str ="";
        for (int i=0; i<this.neighbors.length; i++){
            str += neighbors[i].name+"\n";
        }
        return str;
    }


    Countries[] getNeighbors() {
        return this.neighbors;
    }

    String getName() {
        return this.name;
    }
}

And

import countries.*;
// package countries;

    public class TestCountry extends Country {
    public void run() {

    System.out.println(name);
    System.out.println(population);
    System.out.println(isEuropean);
    System.out.println(inEurope());
    System.out.println(area);

    System.out.println(toString());
    updatePopulation(100);
    System.out.println(getNeighbors());
    System.out.println(getName());
    }

    public static void main(String[] args){
        TestCountry o1 = new TestCountry();
        o1.run();
    }
}

Of course I tried it out and found out that the following lines wouldn't work anymore (if we outcomment package countries; and write import countries.*; instead):

System.out.println(isEuropean);
System.out.println(getNeighbors());
System.out.println(getName());

Can someone explain me why they don't work and what import countries.*; exactly does?

Without modifiers, isEuropean, getName() are having default scope also called package scope. Your test was no longer in the same package as the class therefore it can only access public and protected members (protected because it is subclass of Country. See this: docs.oracle.com/javase/tutorial/java/javaOO/accesscontrol.html — diginoise
– diginoise, Commented Dec 19, 2017 at 16:57

meditat · Accepted Answer · 2017-12-19 18:05:01Z

since you have not set the scope of the String getName(), getNeighbors() method(where it can be accessible), so they have default package scopei.e they can be used within the same package.same is with the variable isEuropean.so you can not use them in another package. But all the protected member of your Countries class can be accessible since your test class is extending Countries class

Access Levels

+---------------+-------+---------+----------+-------+
| modifiers     | class | package | subclass | world |
+---------------+-------+---------+----------+-------+
| Public        |   Y   |    Y    |    Y     |   Y   |
+---------------+-------+---------+----------+-------+
| Protected     |   Y   |    Y    |    Y     |   N   |
+-----------------------+---------+----------+-------+
| Private       |   Y   |    N    |    N     |   N   |
+---------------+-------+---------+----------+-------+
| No Modifiers  |   Y   |    Y    |    N     |   N   |
+---------------+-------+---------+----------+-------+

riteshmaurya · Accepted Answer · 2017-12-19 17:07:01Z

1

System.out.println(getNeighbors());

answered Dec 19, 2017 at 17:07

riteshmaurya

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