Hello, I started Processing yesterday. I have imported CSV data into 2d array using a good public code, but I failed in reading it. Could you tell me why first "println(csv[0][0]); " works, but second "println(csv[0][0]); " makes error? 

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1. String lines[];
2. int csvWidth;
3. String [][] csv;
4. 
   
5. void setup() {
6.   String lines[] = loadStrings("Book1.csv");
7.   String [][] csv;
8.   int csvWidth=0;
9.   
10.   //calculate max width of csv file
11.   for (int i=0; i < lines.length; i++) {
12.     String [] chars=split(lines[i],',');
13.     if (chars.length>csvWidth){
14.       csvWidth=chars.length;
15.     }
16.   }
17. 
    
18.   //create csv array based on # of rows and columns in csv file
19.   csv = new String [lines.length][csvWidth];
20. 
    
21.   //parse values into 2d array
22.   for (int i=0; i < lines.length; i++) {
23.     String [] temp = new String [lines.length];
24.     temp= split(lines[i], ',');
25.     for (int j=0; j < temp.length; j++){
26.      csv[i][j]=temp[j];
27.     }
28.   }
29.   println(csv[0][0]);                        // O.K. 
30. } 
31. 
    
32. void draw(){
33.   background(0);
34.   println(csv[0][0]);                        // NullPointerException  
35. }