Need help on a exception error

Question

here s my program my problem is i keep getting a index out of bounds error and have no clue why heres the error followed by the code
thanks in advance for any help
java.lang.ArrayIndexOutOfBoundsException
     at graphics_class2.init(graphics_class2.java:37)
     at sun.applet.AppletPanel.run(AppletPanel.java:344)
     at java.lang.Thread.run(Thread.java:484)
Exit code: 0
No Errors
public class graphics_class2 extends Applet {
int dumyvarX = 150 ;
int dumyvarY = 150 ;
int n= 0;
int j = 0;
int i = 0;
int[] nx ;
int[] ny ;
int[] x ;
int[] y ;
int polygonpositionX = 100;
int polygonpositionY = 100;
int centerpointX = 100;
int centerpointY = 100;
int adjusted_centerpointX = 0;
int adjusted_centerpointY = 0;
int maximum_vertices = 3;
public void init() {
nx = new int[maximum_vertices] ;
ny = new int[maximum_vertices] ;
x = new int[ maximum_vertices] ;
y = new int[ maximum_vertices] ;
nx[0]= 20; nx[1]=40; nx[2]=60; nx[3]=110;
ny[0]= 170; ny[1]=100; ny[2]=170; ny[3]=220;
adjusted_centerpointX = centerpointX + polygonpositionX;
adjusted_centerpointY = centerpointY + polygonpositionY;
for(i = 0; i < maximum_vertices; i++) {
x[i] = nx[v ]+polygonpositionX ; // v is i just to lazy to retype it all out
y[i] = ny[v ]+polygonpositionY ;
public void paint(Graphics g) {
g.setColor(Color.black);
g.setColor(Color.cyan);
for(i = 1; i <= 359; i++){
for(n = 1; n <= maximum_vertices; n++){
dumyvarX = nx[n]+polygonpositionX ;
dumyvarY = ny[n]+polygonpositionY ;
x[n] = (int)(dumyvarX * Math.cos(i)) ; // float or int?
x[n] = (int)(dumyvarY * Math.sin(i)) ;
g.drawPolygon(x,y,maximum_vertices) ;
repaint();
// g.setColor(Color.cyan);
// g.drawPolygon(x,y,maximum_vertices) ;
// g.fillPolygon(x,y,4);
// g.drawLine(centerpointX+polygonpositionX,centerpointY + polygonpositionY,(int)(dumyvarX +(j) * Math.cos(i)), (int)(dumyvarY +(j ) * Math.sin(i)));
// repaint();

Answer 1

Your code:
nx = new int[maximum_vertices] ;
ny = new int[maximum_vertices] ;
x = new int[ maximum_vertices] ;
y = new int[ maximum_vertices] ;
nx[0]= 20; nx[1]=40; nx[2]=60; nx[3]=110;
ny[0]= 170; ny[1]=100; ny[2]=170; ny[3]=220;maximum_vertices is 3 and therefore space for 3 ints is allocated. You try to access 4 (0 -> 3) but there are only 3 (0 -> 2).