import uwcse.graphics.*;
import java.awt.Color;
/**
 * A class to illustrate the 'call by value' concept<br>
 * Write two methods:<ul>
 * <li>changeSign(int someInt) to change the sign of someInt</li>
 * <li>changeColor(Rectangle r) to change the color of r </li>
 * </ul><br>
 * Call both of these methods from another method. See which one
 * has an effect within that other method.
 */

public class CallByValue
{
	/**
     * Call 2 methods: one method takes a primitive type, the other
     * a reference type. See the difference.
     */
    public void callByValueExamples() // complete
	{
		// A method cannot modify the value of an actual parameter
		// if the actual parameter is a primitive type

		// Can't change the sign of i in the method changeSign
		int i = 10;
        System.out.println("Before changeSign: "+i);
        changeSign(i); // i is the primitive type
        System.out.println("After changeSign: "+i);


		// But a method can change the content of an object
        // passed as a reference
		Rectangle r = new Rectangle();
        r.setColor(Color.red);
        System.out.println("Before changeColor: "+r.getColor());
        changeColor(r); // r is a reference to an Rectangle
        System.out.println("After changeColor: "+r.getColor());
	}

    /**
     * Change the sign of the integer
     */
	private void changeSign(int someInt)
	{
		// change the sign of the formal parameter

	}

    /**
     * change the color of the Rectangle to green
     */
	private void changeColor(Rectangle r)
	{
		// Set the color to green

	}
}