<u>Answer:</u>
CIRCLE.JAVA
public class Circle {
<em>private</em><em> </em>double radius;
<em>public</em> Circle(double myRadius) {
radius = myRadius;
private void setRadius(int myRadius){
radius = myRadius;
}
<em>public </em>double getDiameter() {
return radius*2;
}
public double getRadius() {
return radius;
}
<em>public </em> double getPerimeter() {
return Math.PI*getDiameter();
}
<em>public</em> String toString() {
return "Circle with a radius of " + radius;
}
}
CIRCLE TESTER.JAVA
public class CircleTester {
public static void main(String[] args) {
Circle circ = new Circle(10);
circ.radius = 5;
System.out.println(circ);
System.out.println("The diameter is " + circ.getDiameter());
System.out.println("The perimeter is " + circ.getPerimeter())
}
}
<u>Explanation:</u>
public class Circle {
//This could be made private or public.
//Making it private is better
<em>private</em><em> </em>double radius;
//This is a constructor. It should be made public
//since it would most likely be used in another class
//to create an object of this class.
//Making it private means no other external class can create
//an object of this class.
//Since the tester class (CIRCLETESTER.java), as shown on line 3,
// needs to create
//an object of this class, this should be made public
<em>public</em> Circle(double myRadius) {
radius = myRadius;
private void setRadius(int myRadius){
radius = myRadius;
}
//This should be made public since it will be
// used in another class (CIRCLETESTER.java in this case)
<em>public </em>double getDiameter() {
return radius*2;
}
public double getRadius() {
return radius;
}
//This should be made public since it will be
//used in another class (CIRCLETESTER.java)
<em>public </em> double getPerimeter() {
return Math.PI*getDiameter();
}
//The toString() method is the string representation
//of an object and is called when there is an attempt to
//print the object. It should be made public since it will
//be used in another class (CIRCLETESTER.java)
<em>public</em> String toString() {
return "Circle with a radius of " + radius;
}
}
CIRCLE TESTER.JAVA
public class CircleTester {
public static void main(String[] args) {
Circle circ = new Circle(10);
circ.radius = 5;
System.out.println(circ);
System.out.println("The diameter is " + circ.getDiameter());
System.out.println("The perimeter is " + circ.getPerimeter())
}
}
