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Index › Programming Questions & Help › Programs › Null Pointer Exception with 2D objects arrays

p07gbar YaBB Newbies Offline Posts: 3

Null Pointer Exception with 2D objects arrays Feb 8th, 2010, 1:59pm   Quote: public square[][] sqr; void setup() {  size(1000,800);  sqr  = new square[10][10]; } void draw() {  sqr[0][0].Type(); } public class square {  int type;  void Type(int typeIn) { type = typeIn;}  int Type() {return type;}   } I try to run this and I get a Null Pointer Exception...This is a cut down version of a fully working big program. Thanks.

Cedric YaBB Moderator Offline Posts: 1838	Re: Null Pointer Exception with 2D objects arrays Reply #1 - Feb 8th, 2010, 2:14pm   look at this array of objects example. you miss some important parts in setup. you need to initialize every instance not only 10,10 in this case use 2 loops like in the example. http://processing.org/learning/basics/arrayobjects.html
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alvaro Junior Member Offline Posts: 85 Berlin	Re: Null Pointer Exception with 2D objects arrays Reply #2 - Feb 8th, 2010, 2:15pm   Code: // declare the array public square[][] sqr; void setup() { // initialize the ARRAY sqr  = new square[10][10]; // initialize each square object for (int i = 0; i < 10; i++) {   for (int j = 0; j < 10; j++) {     sqr[i][j] = new square();   } } } ....

p07gbar YaBB Newbies Offline Posts: 3	Re: Null Pointer Exception with 2D objects arrays Reply #3 - Feb 9th, 2010, 9:13am   Many thanks, I wasnt clear that I needed to define every instace post intailisation.