Cuestionario 10. 1Z0-808

What is the name of the Java concept that uses access modifiers to protect variables and hide them within a class?

Given the code fragment:

abstract class Planet {
 
    protected void revolve() { // line n1
 
    }
 
    abstract void rotate(); // line n2
}
 
class Earth extends Planet {
 
    void revolve() { // line n3
 
    }
 
    protected void rotate() { // line n4
 
    }
}

Which two modifications, made independently, enable the code to compile?

Given:

class Vehicle {
 
    String type = "4W";
    int maxSpeed = 100;
 
    Vehicle(String type, int maxSpeed) {
        this.type = type;
        this.maxSpeed = maxSpeed;
    }
}
 
class Car extends Vehicle {
 
    String trans;
 
    Car(String trans) { // line n1
        this.trans = trans;
    }
 
    Car(String type, int maxSpeed, String trans) {
        super(type, maxSpeed);
        this(trans); //line n2
    }
}

And given the code fragment:

public static void main(String[] args) {
    Car c1 = new Car("Auto");
    Car c2 = new Car("4W", 150, "Manual");
    System.out.println(c1.type + " " + c1.maxSpeed + " " + c1.trans);
    System.out.println(c2.type + " " + c2.maxSpeed + " " + c2.trans);
}

What is the result?

Given the code fragment:

class X {
    public void printFileContent() {
        /* code goes here */
        throw new IOException();
    }
}
public class Test {
    public static void main(String[] args) {
        X xobj = new X();
        xobj.printFileContent();
    }
}

Which two modifications should you make so that the code compiles successfully?