Invalid Type Expression Compile Error

Question

Hi,
Can anybody help?
C:\java>javac PointRectangle.java
PointRectangle.java:74: Invalid type expression.
loc=new Point(xCoord,yCoord)//*****
^
1 error
Create class Point which replaces xCoord & yCoord and
is used in class Shapes
TEST: Has been tested independently
import javax.swing.JApplet;
import java.awt.Graphics;
class Point
     private int xCoord;
     private int yCoord;
     Point( ){}
     Point(int xCoord, int yCoord)
set(xCoord,yCoord);
     public void set(int x, int y)
xCoord = x;
     yCoord = y;
     public int getX()
return xCoord;
     public int getY()
return yCoord;
Create new version of Rectangle by eliminating anything common to all Shapes
TEST: class Rectangle has a point;
class Rectangle
private static int counter = 0;
//xCoord = x;
//yCoord = y;
private Point loc;//*****
private int width;
private int height;
Rectangle( )
++counter;
Rectangle(int x, int y, int w, int h)
//xCoord = x;
//yCoord = y;
loc = new Point(x,y)//*****
width = w;
height = h;
     ++counter;
//Use any set() if you don't want to initialize dMembrs
//through c_tors
//set rectangle at a given x & y coord
public void setLocation(int x, int y)
     //xCoord = x;
     //yCoord = y;
loc.set(x,y);//*****
public void setDimension(int w, int h)
     width = w;
height = h;
public void set(int x, int y, int w, int h)
//xCoord = x;
//yCoord = y;
loc.set(x,y);//*****
width = w;
height = h;
//Use get() if you don't want to access dMembrs directly
//public int getX() {return xCoord;}
public int getX() {return loc.getX();}//*****
//public int getY() {return yCoord;}
public int getY() {return loc.getY();}//*****
public int getWidth() {return width;}
public int getHeight() {return height;}
//Rectangle's perimeter
public int perimeter()
return (2 * width) + (2 * height);
//Rectangle's area
public int area()
return width * height;
//output
     public void draw(Graphics g)
//g.drawRect(xCoord,yCoord,width,height);
g.drawRect(loc.getX(),loc.getY(),width,height);//*****
//Convert String
     public String toString()
     //return
// "(("+ xCoord +", "+ yCoord +"), "+ width +","+ height +")";
     return
"(("+ loc.getX() +", "+ loc.getY() +"), "+ width +","+ height +")";//*****
//returns number of rectangels created
     public static int recCount()
return counter;
}//End Class Rectangle
public class PointRectangle extends JApplet
Rectangle r1;
Rectangle r2;
Rectangle r3;
public void init()
//create Rectangles
r1 = new Rectangle( );
r1.set(20,200,50,40);
r2 = new Rectangle(20,300,80,60);//x,y,width,height
r3 = new Rectangle();
} //end init()
public void paint(Graphics g)
g.drawString("r1 Area: " + r1.area(),20,50);
g.drawString("r1 Perimeter: " + r1.perimeter(),20,75);
g.drawString
("r1 arguments in r1.set(): " + r1.toString(),20,100);
g.drawString
("r2: xCoord =" + r2.getX() + " yCoord=" +r2.getY()
+ " Width =" + r2.getWidth()
+ " Height=" + r2.getHeight(), 20,125);
r3.setLocation(20,400);
r3.setDimension(100,150);
g.drawString
("r3: xCoord =" + r3.getX() + " yCoord=" + r3.getY()
+ " Width =" + r3.getWidth()
+ " Height=" + r3.getHeight(), 20,150);
g.drawString
("r's created: "+Rectangle.recCount(),20,175);
r1.draw(g);
r2.draw(g);
r3.draw(g);
} //end paint()

Answer 1

Are you referring to the following:I'm not; the message you posted is... :)
There's only one place where you handle an object reference in that code: "loc.set(x,y);". So it must be that the reference "loc" is null; you haven't determined which object it should point to so it doesn't point to any object.
Looking deeper at the code above, it's not a big surprise as you never actually assign loc to anything. The only place where you do "loc = ..." is a constructor which you don't seem to use.